Add option cover for ebook generation
Add option cover for ebook generation

justinleoye/gitbook,strawluffy/gitbook,FKV587/gitbook,iflyup/gitbook,anrim/gitbook,wewelove/gitbook,tzq668766/gitbook,iamchenxin/gitbook,iflyup/gitbook,escopecz/documentation,escopecz/documentation,mautic/documentation,sudobashme/gitbook,thelastmile/gitbook,palerdot/gitbook,Keystion/gitbook,minghe/gitbook,ZachLamb/gitbook,vehar/gitbook,JozoVilcek/gitbook,alex-dixon/gitbook,gencer/gitbook,hujianfei1989/gitbook,lucciano/gitbook,ryanswanson/gitbook,codepiano/gitbook,hongbinz/gitbook,tshoper/gitbook,xxxhycl2010/gitbook,gdbooks/gitbook,rohan07/gitbook,npracht/documentation,Abhikos/gitbook,guiquanz/gitbook,justinleoye/gitbook,xcv58/gitbook,jasonslyvia/gitbook,svenkatreddy/gitbook,intfrr/gitbook,megumiteam/documentation,megumiteam/documentation,snowsnail/gitbook,gaearon/gitbook,xcv58/gitbook,palerdot/gitbook,npracht/documentation,haamop/documentation,hongbinz/gitbook,sunlianghua/gitbook,grokcoder/gitbook,grokcoder/gitbook,jocr1627/gitbook,2390183798/gitbook,minghe/gitbook,switchspan/gitbook,a-moses/gitbook,shibe97/gitbook,hujianfei1989/gitbook,lucciano/gitbook,sunlianghua/gitbook,bjlxj2008/gitbook,kamyu104/gitbook,nycitt/gitbook,gdbooks/gitbook,OriPekelman/gitbook,tshoper/gitbook,snowsnail/gitbook,wewelove/gitbook,jasonslyvia/gitbook,guiquanz/gitbook,xiongjungit/gitbook,boyXiong/gitbook,athiruban/gitbook,rohan07/gitbook,bradparks/gitbook,OriPekelman/gitbook,intfrr/gitbook,tzq668766/gitbook,qingying5810/gitbook,a-moses/gitbook,xiongjungit/gitbook,FKV587/gitbook,bjlxj2008/gitbook,mautic/documentation,youprofit/gitbook,vehar/gitbook,bradparks/gitbook,mruse/gitbook,JohnTroony/gitbook,gencer/gitbook,webwlsong/gitbook,sudobashme/gitbook,ferrior30/gitbook,mruse/gitbook,boyXiong/gitbook,jocr1627/gitbook,JohnTroony/gitbook,thelastmile/gitbook,GitbookIO/gitbook,youprofit/gitbook,yaonphy/SwiftBlog,nycitt/gitbook,ZachLamb/gitbook,webwlsong/gitbook,codepiano/gitbook,svenkatreddy/gitbook,alex-dixon/gitbook,kamyu104/gitbook,iamchenxin/gitbook,xxxhycl2010/gitbook,qingying5810/gitbook,2390183798/gitbook,gaearon/gitbook,ferrior30/gitbook,CN-Sean/gitbook,shibe97/gitbook,switchspan/gitbook,athiruban/gitbook,haamop/documentation,CN-Sean/gitbook