[doc] add "model zoo" in the navigation bar (#4122)
[doc] add "model zoo" in the navigation bar (#4122)


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