MNIST tutorial improvements. (#6232)
MNIST tutorial improvements. (#6232)

* Initial clean up of mnist tutorial

* More fixes + Image for MLP

* More content

* Image for CNN

* temporary: madjam's fork for images.

* temporary: madjam's fork for images.

* Image captions

* Formatting fix

* Format fix

* More content improvements

* Formatting fixes

* Content improvements

* code fix

* typo fix

* image borders

* fix img rendering

* fix img rendering

* Image box for mnist examples

* updates based on Bhavin's feedback

* training data -> train data

* Updates based on @zackchase feedback

madjam/mxnet,smolix/incubator-mxnet,jermainewang/mxnet,kkk669/mxnet,zhreshold/mxnet,navrasio/mxnet,TuSimple/mxnet,apaleyes/mxnet,tornadomeet/mxnet,stefanhenneking/mxnet,stefanhenneking/mxnet,ShownX/incubator-mxnet,ShownX/incubator-mxnet,navrasio/mxnet,tlby/mxnet,reminisce/mxnet,precedenceguo/mxnet,solin319/incubator-mxnet,likelyzhao/mxnet,indhub/mxnet,LinkHS/incubator-mxnet,kkk669/mxnet,tornadomeet/mxnet,piiswrong/mxnet,jennyzhang0215/incubator-mxnet,ShownX/incubator-mxnet,coder-james/mxnet,yajiedesign/mxnet,piiswrong/mxnet,lxn2/mxnet,antoan2/incubator-mxnet,TuSimple/mxnet,Prasad9/incubator-mxnet,DR08/mxnet,ptrendx/mxnet,solin319/incubator-mxnet,thirdwing/mxnet,kkk669/mxnet,larroy/mxnet,EvanzzzZ/mxnet,tornadomeet/mxnet,Mega-DatA-Lab/mxnet,dmlc/mxnet,vikingMei/mxnet,precedenceguo/mxnet,wangyum/mxnet,weleen/mxnet,jermainewang/mxnet,navrasio/mxnet,yajiedesign/mxnet,eric-haibin-lin/mxnet,hesseltuinhof/mxnet,likelyzhao/mxnet,ykim362/mxnet,hesseltuinhof/mxnet,jennyzhang0215/incubator-mxnet,ptrendx/mxnet,yuruofeifei/mxnet,hpi-xnor/BMXNet,kevinthesun/mxnet,formath/mxnet,Prasad9/incubator-mxnet,weleen/mxnet,hesseltuinhof/mxnet,arikpoz/mxnet,Ldpe2G/mxnet,antoan2/incubator-mxnet,Mega-DatA-Lab/mxnet,Prasad9/incubator-mxnet,CodingCat/mxnet,sergeykolychev/mxnet,LinkHS/incubator-mxnet,piiswrong/mxnet,Northrend/mxnet,leezu/mxnet,mbaijal/incubator-mxnet,jiajiechen/mxnet,ShownX/incubator-mxnet,reminisce/mxnet,nicklhy/mxnet,tlby/mxnet,apache/incubator-mxnet,coder-james/mxnet,ykim362/mxnet,Ldpe2G/mxnet,hpi-xnor/BMXNet,ZihengJiang/mxnet,gautamkmr/incubator-mxnet,jamesliu/mxnet,likelyzhao/mxnet,madjam/mxnet,arikpoz/mxnet,danithaca/mxnet,formath/mxnet,tlby/mxnet,DickJC123/mxnet,luoyetx/mxnet,arank/mxnet,antoan2/incubator-mxnet,vikingMei/mxnet,coder-james/mxnet,ykim362/mxnet,sxjscience/mxnet,fullfanta/mxnet,luoyetx/mxnet,yajiedesign/mxnet,hpi-xnor/BMXNet,apaleyes/mxnet,CodingCat/mxnet,kevinthesun/mxnet,CodingCat/mxnet,apaleyes/mxnet,ptrendx/mxnet,reminisce/mxnet,zhreshold/mxnet,fullfanta/mxnet,hotpxl/mxnet,navrasio/mxnet,jennyzhang0215/incubator-mxnet,stefanhenneking/mxnet,precedenceguo/mxnet,tornadomeet/mxnet,ZihengJiang/mxnet,fullfanta/mxnet,vikingMei/mxnet,CodingCat/mxnet,pluskid/mxnet,ZihengJiang/mxnet,rahul003/mxnet,nicklhy/mxnet,antoan2/incubator-mxnet,larroy/mxnet,larroy/mxnet,leezu/mxnet,mbaijal/incubator-mxnet,TuSimple/mxnet,antoan2/incubator-mxnet,gautamkmr/incubator-mxnet,weleen/mxnet,hotpxl/mxnet,arikpoz/mxnet,crazy-cat/incubator-mxnet,larroy/mxnet,Northrend/mxnet,EvanzzzZ/mxnet,thirdwing/mxnet,hotpxl/mxnet,ptrendx/mxnet,zhreshold/mxnet,yuruofeifei/mxnet,Ldpe2G/mxnet,xcgoner/dist-mxnet,nicklhy/mxnet,ShownX/incubator-mxnet,LinkHS/incubator-mxnet,kkk669/mxnet,wangyum/mxnet,saurabh3949/mxnet,EvanzzzZ/mxnet,piiswrong/mxnet,ykim362/mxnet,leezu/mxnet,EvanzzzZ/mxnet,formath/mxnet,larroy/mxnet,Mega-DatA-Lab/mxnet,zhreshold/mxnet,ShownX/incubator-mxnet,navrasio/mxnet,Northrend/mxnet,LinkHS/incubator-mxnet,ykim362/mxnet,ShownX/incubator-mxnet,szha/mxnet,xcgoner/dist-mxnet,solin319/incubator-mxnet,reminisce/mxnet,luoyetx/mxnet,piiswrong/mxnet,DickJC123/mxnet,hotpxl/mxnet,danithaca/mxnet,stefanhenneking/mxnet,larroy/mxnet,yuruofeifei/mxnet,wangyum/mxnet,solin319/incubator-mxnet,Mega-DatA-Lab/mxnet,kevinthesun/mxnet,thirdwing/mxnet,luoyetx/mxnet,jamesliu/mxnet,tornadomeet/mxnet,vikingMei/mxnet,jermainewang/mxnet,thirdwing/mxnet,sergeykolychev/mxnet,TuSimple/mxnet,szha/mxnet,smolix/incubator-mxnet,formath/mxnet,dmlc/mxnet,kkk669/mxnet,arank/mxnet,ykim362/mxnet,apaleyes/mxnet,pluskid/mxnet,fullfanta/mxnet,Ldpe2G/mxnet,arikpoz/mxnet,xcgoner/dist-mxnet,eric-haibin-lin/mxnet,EvanzzzZ/mxnet,pluskid/mxnet,yuruofeifei/mxnet,rahul003/mxnet,jiajiechen/mxnet,piiswrong/mxnet,tlby/mxnet,sxjscience/mxnet,precedenceguo/mxnet,kevinthesun/mxnet,hesseltuinhof/mxnet,formath/mxnet,smolix/incubator-mxnet,lxn2/mxnet,crazy-cat/incubator-mxnet,precedenceguo/mxnet,lxn2/mxnet,DR08/mxnet,hpi-xnor/BMXNet,tornadomeet/mxnet,solin319/incubator-mxnet,xcgoner/dist-mxnet,arikpoz/mxnet,jennyzhang0215/incubator-mxnet,Northrend/mxnet,wangyum/mxnet,danithaca/mxnet,TuSimple/mxnet,jennyzhang0215/incubator-mxnet,jermainewang/mxnet,leezu/mxnet,Ldpe2G/mxnet,jamesliu/mxnet,nicklhy/mxnet,gautamkmr/incubator-mxnet,kkk669/mxnet,kkk669/mxnet,nicklhy/mxnet,stefanhenneking/mxnet,ForkedReposBak/mxnet,yajiedesign/mxnet,lxn2/mxnet,mbaijal/incubator-mxnet,Ldpe2G/mxnet,sergeykolychev/mxnet,TuSimple/mxnet,kevinthesun/mxnet,navrasio/mxnet,zhreshold/mxnet,dmlc/mxnet,fullfanta/mxnet,ZihengJiang/mxnet,sergeykolychev/mxnet,danithaca/mxnet,crazy-cat/incubator-mxnet,arank/mxnet,reminisce/mxnet,precedenceguo/mxnet,saurabh3949/mxnet,dmlc/mxnet,hpi-xnor/BMXNet,hotpxl/mxnet,eric-haibin-lin/mxnet,formath/mxnet,crazy-cat/incubator-mxnet,larroy/mxnet,larroy/mxnet,crazy-cat/incubator-mxnet,tlby/mxnet,ForkedReposBak/mxnet,apaleyes/mxnet,precedenceguo/mxnet,xcgoner/dist-mxnet,DickJC123/mxnet,hpi-xnor/BMXNet,gautamkmr/incubator-mxnet,likelyzhao/mxnet,sergeykolychev/mxnet,jamesliu/mxnet,DR08/mxnet,ykim362/mxnet,ptrendx/mxnet,dmlc/mxnet,jiajiechen/mxnet,luoyetx/mxnet,likelyzhao/mxnet,thirdwing/mxnet,tlby/mxnet,mbaijal/incubator-mxnet,sxjscience/mxnet,Mega-DatA-Lab/mxnet,kkk669/mxnet,Ldpe2G/mxnet,precedenceguo/mxnet,jiajiechen/mxnet,ForkedReposBak/mxnet,indhub/mxnet,stefanhenneking/mxnet,kevinthesun/mxnet,reminisce/mxnet,fullfanta/mxnet,EvanzzzZ/mxnet,CodingCat/mxnet,luoyetx/mxnet,ForkedReposBak/mxnet,ForkedReposBak/mxnet,danithaca/mxnet,szha/mxnet,ForkedReposBak/mxnet,weleen/mxnet,LinkHS/incubator-mxnet,ForkedReposBak/mxnet,ZihengJiang/mxnet,xcgoner/dist-mxnet,CodingCat/mxnet,leezu/mxnet,madjam/mxnet,lxn2/mxnet,hotpxl/mxnet,crazy-cat/incubator-mxnet,apache/incubator-mxnet,danithaca/mxnet,arikpoz/mxnet,solin319/incubator-mxnet,ptrendx/mxnet,piiswrong/mxnet,yajiedesign/mxnet,nicklhy/mxnet,madjam/mxnet,szha/mxnet,nicklhy/mxnet,sxjscience/mxnet,madjam/mxnet,gautamkmr/incubator-mxnet,vikingMei/mxnet,apaleyes/mxnet,TuSimple/mxnet,Prasad9/incubator-mxnet,stefanhenneking/mxnet,solin319/incubator-mxnet,saurabh3949/mxnet,tornadomeet/mxnet,navrasio/mxnet,DR08/mxnet,arikpoz/mxnet,DR08/mxnet,jermainewang/mxnet,luoyetx/mxnet,antoan2/incubator-mxnet,saurabh3949/mxnet,xcgoner/dist-mxnet,jiajiechen/mxnet,ykim362/mxnet,danithaca/mxnet,Ldpe2G/mxnet,Northrend/mxnet,saurabh3949/mxnet,likelyzhao/mxnet,ptrendx/mxnet,jamesliu/mxnet,rahul003/mxnet,vikingMei/mxnet,piiswrong/mxnet,xcgoner/dist-mxnet,thirdwing/mxnet,jermainewang/mxnet,hotpxl/mxnet,mbaijal/incubator-mxnet,hpi-xnor/BMXNet,hesseltuinhof/mxnet,antoan2/incubator-mxnet,Prasad9/incubator-mxnet,sxjscience/mxnet,jamesliu/mxnet,crazy-cat/incubator-mxnet,arikpoz/mxnet,piiswrong/mxnet,antoan2/incubator-mxnet,sxjscience/mxnet,coder-james/mxnet,pluskid/mxnet,wangyum/mxnet,mbaijal/incubator-mxnet,Northrend/mxnet,LinkHS/incubator-mxnet,dmlc/mxnet,Mega-DatA-Lab/mxnet,madjam/mxnet,pluskid/mxnet,eric-haibin-lin/mxnet,madjam/mxnet,Mega-DatA-Lab/mxnet,coder-james/mxnet,hesseltuinhof/mxnet,wangyum/mxnet,DR08/mxnet,DR08/mxnet,Northrend/mxnet,pluskid/mxnet,szha/mxnet,EvanzzzZ/mxnet,reminisce/mxnet,ShownX/incubator-mxnet,mbaijal/incubator-mxnet,saurabh3949/mxnet,jiajiechen/mxnet,hesseltuinhof/mxnet,lxn2/mxnet,xcgoner/dist-mxnet,hpi-xnor/BMXNet,Northrend/mxnet,lxn2/mxnet,danithaca/mxnet,leezu/mxnet,reminisce/mxnet,ptrendx/mxnet,indhub/mxnet,vikingMei/mxnet,gautamkmr/incubator-mxnet,tornadomeet/mxnet,jennyzhang0215/incubator-mxnet,gautamkmr/incubator-mxnet,yuruofeifei/mxnet,apaleyes/mxnet,coder-james/mxnet,hotpxl/mxnet,jennyzhang0215/incubator-mxnet,pluskid/mxnet,madjam/mxnet,precedenceguo/mxnet,apache/incubator-mxnet,jamesliu/mxnet,weleen/mxnet,wangyum/mxnet,formath/mxnet,ForkedReposBak/mxnet,leezu/mxnet,rahul003/mxnet,tlby/mxnet,lxn2/mxnet,yuruofeifei/mxnet,tlby/mxnet,zhreshold/mxnet,eric-haibin-lin/mxnet,smolix/incubator-mxnet,arank/mxnet,CodingCat/mxnet,indhub/mxnet,jennyzhang0215/incubator-mxnet,apache/incubator-mxnet,dmlc/mxnet,saurabh3949/mxnet,solin319/incubator-mxnet,fullfanta/mxnet,EvanzzzZ/mxnet,mbaijal/incubator-mxnet,Ldpe2G/mxnet,yajiedesign/mxnet,jermainewang/mxnet,smolix/incubator-mxnet,rahul003/mxnet,reminisce/mxnet,eric-haibin-lin/mxnet,Northrend/mxnet,luoyetx/mxnet,coder-james/mxnet,kevinthesun/mxnet,jamesliu/mxnet,jiajiechen/mxnet,wangyum/mxnet,solin319/incubator-mxnet,yajiedesign/mxnet,zhreshold/mxnet,zhreshold/mxnet,szha/mxnet,coder-james/mxnet,arank/mxnet,jennyzhang0215/incubator-mxnet,weleen/mxnet,yuruofeifei/mxnet,ZihengJiang/mxnet,CodingCat/mxnet,zhreshold/mxnet,lxn2/mxnet,luoyetx/mxnet,kkk669/mxnet,mbaijal/incubator-mxnet,nicklhy/mxnet,gautamkmr/incubator-mxnet,weleen/mxnet,vikingMei/mxnet,jiajiechen/mxnet,indhub/mxnet,szha/mxnet,sergeykolychev/mxnet,saurabh3949/mxnet,nicklhy/mxnet,smolix/incubator-mxnet,ForkedReposBak/mxnet,ZihengJiang/mxnet,rahul003/mxnet,indhub/mxnet,rahul003/mxnet,ZihengJiang/mxnet,formath/mxnet,Prasad9/incubator-mxnet,tlby/mxnet,dmlc/mxnet,arank/mxnet,DR08/mxnet,eric-haibin-lin/mxnet,coder-james/mxnet,sxjscience/mxnet,formath/mxnet,TuSimple/mxnet,weleen/mxnet,smolix/incubator-mxnet,eric-haibin-lin/mxnet,likelyzhao/mxnet,likelyzhao/mxnet,saurabh3949/mxnet,leezu/mxnet,danithaca/mxnet,TuSimple/mxnet,fullfanta/mxnet,TuSimple/mxnet,Mega-DatA-Lab/mxnet,arikpoz/mxnet,szha/mxnet,jamesliu/mxnet,ptrendx/mxnet,LinkHS/incubator-mxnet,pluskid/mxnet,sergeykolychev/mxnet,likelyzhao/mxnet,thirdwing/mxnet,DR08/mxnet,stefanhenneking/mxnet,ShownX/incubator-mxnet,thirdwing/mxnet,sergeykolychev/mxnet,kevinthesun/mxnet,crazy-cat/incubator-mxnet,antoan2/incubator-mxnet,Prasad9/incubator-mxnet,dmlc/mxnet,smolix/incubator-mxnet,crazy-cat/incubator-mxnet,Prasad9/incubator-mxnet,arank/mxnet,yuruofeifei/mxnet,gautamkmr/incubator-mxnet,thirdwing/mxnet,stefanhenneking/mxnet,leezu/mxnet,pluskid/mxnet,jiajiechen/mxnet,wangyum/mxnet,DickJC123/mxnet,sergeykolychev/mxnet,tornadomeet/mxnet,sxjscience/mxnet,yajiedesign/mxnet,ykim362/mxnet,sxjscience/mxnet,apaleyes/mxnet,weleen/mxnet,reminisce/mxnet,jermainewang/mxnet,jermainewang/mxnet,EvanzzzZ/mxnet,eric-haibin-lin/mxnet,arank/mxnet,larroy/mxnet,ptrendx/mxnet,hotpxl/mxnet,hesseltuinhof/mxnet,LinkHS/incubator-mxnet,kevinthesun/mxnet,fullfanta/mxnet,indhub/mxnet,navrasio/mxnet,Mega-DatA-Lab/mxnet,smolix/incubator-mxnet,apaleyes/mxnet,ZihengJiang/mxnet,vikingMei/mxnet,LinkHS/incubator-mxnet,rahul003/mxnet,tlby/mxnet,indhub/mxnet,indhub/mxnet,szha/mxnet,Prasad9/incubator-mxnet,CodingCat/mxnet,hesseltuinhof/mxnet,arank/mxnet,yajiedesign/mxnet,madjam/mxnet,hpi-xnor/BMXNet,yuruofeifei/mxnet,rahul003/mxnet,navrasio/mxnet