docs: include backup github-pages Gemfile
docs: include backup github-pages Gemfile

Fixes #3985

tomjohnson1492/jekyll,noikiy/jekyll,jekyll/jekyll,jekyll/jekyll,likong/jekyll,stomar/jekyll,ajhit406/jekyll,brint/jekyll,howkj1/jekyll,ryanshaw/jekyll,alex-kovac/jekyll,jeffkole/jekyll,noikiy/jekyll,rasa2011/rasa2011.github.io,nasht00/jekyll,Strangehill/jekyll,MauroMrod/jekyll,codeclimate-testing/jekyll,darwin/jekyll,alex-kovac/jekyll,MauroMrod/jekyll,Kinghack/kinghack.github.com,jmepg/jekyll,derekgottlieb/jekyll,howkj1/jekyll,nickg33/jekyll,yihangho/jekyll,gencer/jekyll,floydpraveen/jekyll,ducktyper/jekyll,pmarsceill/jekyll,yihangho/jekyll,tillgrallert/jekyll,ajhit406/jekyll,pmarsceill/jekyll,tomjohnson1492/jekyll,derekgottlieb/jekyll,princeofdarkness76/jekyll,xcatliu/jekyllcn,kuangyeheng/jekyll,Teino1978-Corp/Teino1978-Corp-jekyll,rebornix/jekyll,ryanshaw/jekyll,Strangehill/jekyll,alfredxing/jekyll,CPVPLachlan/CPVP-Blog,alex-kovac/jekyll,PepSalehi/jekyll,codeclimate-testing/jekyll,jmepg/jekyll,zsyed91/jekyll,xiebinhqy/jklly_china,alex-kovac/jekyll,stomar/jekyll,tillgrallert/jekyll,tomjohnson1492/jekyll,nickg33/jekyll,MauroMrod/jekyll,Kinghack/kinghack.github.com,PepSalehi/jekyll,xcatliu/jekyllcn,rlugojr/jekyll,tomjohnson1492/jekyll,hartmel/jekyll,nasht00/jekyll,anthonyrosengren/grasshoppergathering2.github-io,nasht00/jekyll,ryanshaw/jekyll,gencer/jekyll,gencer/jekyll,yihangho/jekyll,brint/jekyll,gaosboy/jekyll,Strangehill/jekyll,pmarsceill/jekyll,getandpost/jekyll.github.io,jeffkole/jekyll,aarvay/jekyll,gencer/jekyll,superve/jekyll,larryfox/jekyll,anthonyrosengren/grasshoppergathering2.github-io,ajhit406/jekyll,PepSalehi/jekyll,ducktyper/jekyll,larryfox/jekyll,CPVPLachlan/CPVP-Blog,dansef/jekyll,rasa2011/rasa2011.github.io,jaybe-jekyll/jekyll,Strangehill/jekyll,thetaxman/jekyll,zsyed91/jekyll,Teino1978-Corp/Teino1978-Corp-jekyll,tomjohnson1492/jekyll,xiebinhqy/jklly_china,jaybe-jekyll/jekyll,rebornix/jekyll,jmepg/jekyll,dansef/jekyll,stomar/jekyll,FlyingWHR/jekyll,ZDroid/jekyll,aarvay/jekyll,gaosboy/jekyll,princeofdarkness76/jekyll,codeclimate-testing/jekyll,howkj1/jekyll,jaybe-jekyll/jekyll,zsyed91/jekyll,thetaxman/jekyll,darwin/jekyll,x-way/jekyll,aarvay/jekyll,princeofdarkness76/jekyll,mrb/jekyll,thetaxman/jekyll,xiebinhqy/jklly_china,FlyingWHR/jekyll,brint/jekyll,hartmel/jekyll,floydpraveen/jekyll,ZDroid/jekyll,mrb/jekyll,x-way/jekyll,x-way/jekyll,rasa2011/rasa2011.github.io,jeffkole/jekyll,nasht00/jekyll,noikiy/jekyll,nickg33/jekyll,x-way/jekyll,noikiy/jekyll,CPVPLachlan/CPVP-Blog,floydpraveen/jekyll,Strangehill/jekyll,LeuisKen/jekyllcn,chrisfinazzo/jekyll,superve/jekyll,chrisfinazzo/jekyll,LeuisKen/jekyllcn,Teino1978-Corp/Teino1978-Corp-jekyll,getandpost/jekyll.github.io,likong/jekyll,gaosboy/jekyll,yhironaka/yhironaka.github.io,rlugojr/jekyll,fulldecent/jekyll,getandpost/jekyll.github.io,kuangyeheng/jekyll,fulldecent/jekyll,Kinghack/kinghack.github.com,mrb/jekyll,darwin/jekyll,chrisfinazzo/jekyll,alfredxing/jekyll,tillgrallert/jekyll,xiebinhqy/jklly_china,bsmr-ruby/jekyll,fulldecent/jekyll,ajhit406/jekyll,mrb/jekyll,bsmr-ruby/jekyll,zsyed91/jekyll,gencer/jekyll,jekyll/jekyll,rebornix/jekyll,alex-kovac/jekyll,sanxore/sanxore.github.com,larryfox/jekyll,alfredxing/jekyll,stomar/jekyll,sasongkojati/jekyll,sanxore/sanxore.github.com,ZDroid/jekyll,sasongkojati/jekyll,rlugojr/jekyll,Teino1978-Corp/jekyll,jekyll/jekyll,fulldecent/jekyll,sasongkojati/jekyll,tillgrallert/jekyll,bsmr-ruby/jekyll,sanxore/sanxore.github.com,ryanshaw/jekyll,superve/jekyll,ducktyper/jekyll,floydpraveen/jekyll,tillgrallert/jekyll,jaybe-jekyll/jekyll,Teino1978-Corp/jekyll,jeffkole/jekyll,derekgottlieb/jekyll,LeuisKen/jekyllcn,Teino1978-Corp/jekyll,FlyingWHR/jekyll,dansef/jekyll,likong/jekyll,xcatliu/jekyllcn,derekgottlieb/jekyll,xcatliu/jekyllcn,hartmel/jekyll,kuangyeheng/jekyll,pmarsceill/jekyll,bsmr-ruby/jekyll,anthonyrosengren/grasshoppergathering2.github-io,princeofdarkness76/jekyll,chrisfinazzo/jekyll,alfredxing/jekyll,rlugojr/jekyll,darwin/jekyll,brint/jekyll