Move zsh completion logic to new subcommand: update
Move zsh completion logic to new subcommand: update

Signed-off-by: Steve Durrheimer <a2c1a055e5b399822be341b4e663de3cd05cf8f7@gmail.com>

x1022as/docker,erikstmartin/docker,laijs/docker,KingEmet/docker,miminar/docker,coolljt0725/docker,danyalKhaliq10p/moby,Mokolea/docker,tmp6154/docker,moul/docker,charleszheng44/moby,ibuildthecloud/docker,bearstech/moby,thaJeztah/docker,raja-sami-10p/moby,sarnautov/moby,tklauser/docker,PatrickLang/moby,yasiramin10p/moby,mkumatag/docker,yummypeng/docker,maxamillion/docker,prertik/docker,jwhonce/docker,stevvooe/docker,sterchelen/docker,darrenstahlmsft/docker,rancher/docker,rancher/docker,msabansal/docker,tophj-ibm/moby,duglin/docker,nalind/docker,xuxinkun/docker,hqhq/moby,lixiaobing10051267/docker,justincormack/docker,djs55/docker,erikh/docker,laijs/moby,dmcgowan/docker,rremer/moby,jimjag/docker,crosbymichael/docker,dmcgowan/docker,rhatdan/docker,dsheets/moby,jimjag/docker,q384566678/docker,diogomonica/docker,mtesselH/docker,allencloud/docker,paralin/docker,mstanleyjones/docker,noironetworks/docker,resin-io/docker,gnailuy/docker,nawawi/docker,mtesselH/docker,AkihiroSuda/docker,naveed-jamil-tenpearls/moby,coreos/docker,allencloud/docker,shishir-a412ed/docker,jvanz/docker,prertik/docker,mikedougherty/docker,kencochrane/docker,dccurtis/docker,darrenstahlmsft/docker,KarthikNayak/docker,konstruktoid/docker-upstream,madhanrm/docker,bearstech/moby,paralin/docker,coreos/docker,madhanrm/docker,kolyshkin/docker,mikedougherty/docker,docker/docker,dperny/docker,ripcurld0/moby,docker/docker,Mokolea/docker,konstruktoid/docker-1,kolyshkin/moby,KingEmet/docker,stevvooe/docker,rhatdan/docker,tklauser/docker,yosifkit/docker,scotttlin/docker,alfred-landrum/docker,q384566678/docker,thtanaka/docker,darrenstahlmsft/moby,lixiaobing1/docker,jimjag/docker,akira-baruah/docker,miminar/docker,prertik/docker,kolyshkin/moby,jlhawn/docker,moypray/docker,Mokolea/docker,laijs/moby,nalind/docker,mstanleyjones/docker,vdemeester/docker,jameszhan/docker,YuPengZTE/docker,amatsus/docker,maxamillion/docker,gnailuy/docker,erikstmartin/docker,bonczj/moby-json-file-logger,duglin/docker,ibuildthecloud/docker,crosbymichael/docker,ColinHebert/docker,flavio/docker,jameszhan/docker,bonczj/moby-json-file-logger,Ramzec/docker,coreos/docker,yosifkit/docker,yosifkit/docker,fcrisciani/docker,mtrmac/docker,trebonian/docker,tmp6154/docker,unclejack/docker,msabansal/docker,whuwxl/docker,AkihiroSuda/docker,kolyshkin/moby,dmcgowan/docker,darrenstahlmsft/docker,mixja/docker,HideoYamauchi/docker,moby/moby,bonczj/moby-json-file-logger,resin-io/docker,moul/docker,catinthesky/docker,imkin/moby,tophj-ibm/moby,dccurtis/docker,cyphar/docker,trebonian/docker,lixiaobing1/docker,yasiramin10p/moby,jameszhan/docker,lixiaobing1/docker,tklauser/docker,tianon/docker,naveed-jamil-tenpearls/moby,mixja/docker,erikstmartin/docker,trebonian/docker,Ramzec/docker,shhsu/docker,sterchelen/docker,gjaskiewicz/moby,rhatdan/docker,qudongfang/docker,thtanaka/docker,jthelin/docker,mtesselH/docker,konstruktoid/docker-upstream,michael-holzheu/docker,charleszheng44/moby,moul/docker,ibuildthecloud/docker,unclejack/docker,scotttlin/docker,crosbymichael/docker,YuPengZTE/docker,ColinHebert/docker,coolljt0725/docker,pramodhkp/moby,cyphar/docker,dims/docker,harche/docker,docker/docker,pramodhkp/moby,lixiaobing10051267/docker,PatrickLang/moby,KarthikNayak/docker,justincormack/docker,whuwxl/docker,pradipd/moby,mstanleyjones/docker,JMesser81/docker,x1022as/docker,kojiromike/docker,mikebrow/docker,sdurrheimer/docker,whuwxl/docker,lixiaobing10051267/docker,konstruktoid/docker-upstream,justincormack/docker,naveed-jamil-tenpearls/moby,estesp/docker,dims/docker,rremer/moby,catinthesky/docker,tophj-ibm/docker,YuPengZTE/docker,madhanrm/docker,ffoysal/docker,jimjag/docker,gjaskiewicz/moby,hqhq/moby,ndeloof/docker,darrenstahlmsft/moby,amatsus/docker,fcrisciani/docker,vdemeester/docker,imkin/moby,bearstech/moby,gjaskiewicz/moby,moypray/docker,srust/docker,mtrmac/docker,moby/moby,dims/docker,tophj-ibm/moby,q384566678/docker,resin-io/docker,sdurrheimer/docker,yongtang/docker,yongtang/docker,tophj-ibm/docker,flavio/docker,liaoqingwei/docker,akira-baruah/docker,michael-holzheu/docker,dgageot/docker,jlhawn/docker,mkumatag/docker,thaJeztah/docker,tonistiigi/docker,thtanaka/docker,mahak/docker,coolljt0725/docker,jvanz/docker,darrenstahlmsft/moby,miminar/docker,shishir-a412ed/docker,djs55/docker,haveatry/docker,kencochrane/docker,kolyshkin/docker,ndeloof/docker,moul/docker,Syntaxide/docker,Syntaxide/docker,fcrisciani/docker,tmp6154/docker,srust/docker,mkumatag/docker,moby/moby,konstruktoid/docker-1,erikh/docker,nalind/docker,paralin/docker,sarnautov/moby,estesp/docker,thaJeztah/docker,gschaetz/moby,scotttlin/docker,michael-holzheu/docker,nawawi/docker,msabansal/docker,nawawi/docker,Mokolea/docker,moypray/docker,dperny/docker,mahak/docker,gschaetz/moby,jlhawn/docker,dgageot/docker,mtrmac/docker,noironetworks/docker,nawawi/docker,paralin/docker,SvenDowideit/docker,jvanz/docker,haveatry/docker,diogomonica/docker,KingEmet/docker,tianon/docker,ffoysal/docker,pradipd/moby,x1022as/docker,shhsu/docker,laijs/moby,johnstep/moby-moby,konstruktoid/docker-1,xuxinkun/docker,moby/moby,duglin/docker,srust/docker,allencloud/docker,ffoysal/docker,laijs/docker,danyalKhaliq10p/moby,flavio/docker,sarnautov/moby,yummypeng/docker,PatrickLang/moby,raja-sami-10p/moby,kojiromike/docker,JMesser81/docker,cpuguy83/docker,rremer/moby,cpuguy83/docker,shishir-a412ed/docker,erikh/docker,Ramzec/docker,ripcurld0/moby,POLJM242/docker,cpuguy83/docker,nalind/docker,ndeloof/docker,Ramzec/docker,dgageot/docker,yosifkit/docker,ibuildthecloud/docker,cyphar/docker,HideoYamauchi/docker,imkin/moby,KarthikNayak/docker,diogomonica/docker,johnstep/moby-moby,yongtang/docker,raja-sami-10p/moby,dperny/docker,yummypeng/docker,amatsus/docker,gnailuy/docker,laijs/docker,stevvooe/docker,sdurrheimer/docker,ibuildthecloud/docker,harche/docker,jthelin/docker,mixja/docker,mike1729/docker,liaoqingwei/docker,alfred-landrum/docker,jwhonce/docker,trebonian/docker,unclejack/docker,danyalKhaliq10p/moby,AkihiroSuda/docker,tonistiigi/docker,yasiramin10p/moby,liaoqingwei/docker,SvenDowideit/docker,ColinHebert/docker,xuxinkun/docker,shhsu/docker,hqhq/moby,mike1729/docker,cpuguy83/docker,rancher/docker,johnstep/moby-moby,gnailuy/docker,mahak/docker,mike1729/docker,dsheets/moby,kencochrane/docker,tonistiigi/docker,tophj-ibm/docker,thaJeztah/docker,POLJM242/docker,flavio/docker,JMesser81/docker,catinthesky/docker,djs55/docker,harche/docker,charleszheng44/moby,dsheets/moby,haveatry/docker,gschaetz/moby,HideoYamauchi/docker,jwhonce/docker,dccurtis/docker,mikebrow/docker,alfred-landrum/docker,qudongfang/docker,mikebrow/docker,vdemeester/docker,qudongfang/docker,Syntaxide/docker,bearstech/moby,AkihiroSuda/docker,konstruktoid/docker-upstream,noironetworks/docker,ripcurld0/moby,maxamillion/docker,SvenDowideit/docker,kojiromike/docker,pradipd/moby,pramodhkp/moby,mahak/docker,sterchelen/docker,estesp/docker,mikedougherty/docker