[doc] update faq (#3121)
[doc] update faq (#3121)


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