Make it clear who is doing variable expansion
Make it clear who is doing variable expansion

Add sentece to RUN, CMD, and ENTRYPOINT exec sections making it clear
that it is the shell doing the environment variable expansion.

Signed-off-by: David Dooling <5322ec10610ab977607622218b57799a6a025fab@gmail.com>

x1022as/docker,xuxinkun/docker,nawawi/docker,danyalKhaliq10p/moby,splunk/docker,mahak/docker,resin-io/docker,dgageot/docker,resin-io/docker,bearstech/moby,q384566678/docker,mtrmac/docker,mtanlee/docker,gnailuy/docker,kolyshkin/docker,dccurtis/docker,shhsu/docker,liaoqingwei/docker,icaoweiwei/docker,KingEmet/docker,crosbymichael/docker,sterchelen/docker,darrenstahlmsft/moby,catinthesky/docker,SvenDowideit/docker,nawawi/docker,HideoYamauchi/docker,liaoqingwei/docker,gnailuy/docker,stevvooe/docker,qudongfang/docker,unclejack/docker,unclejack/docker,asbjornenge/docker,justincormack/docker,HuKeping/docker,msabansal/docker,xuxinkun/docker,kolyshkin/docker,mikedougherty/docker,sarnautov/moby,johnstep/moby-moby,hqhq/moby,erikstmartin/docker,portworx/docker,thaJeztah/docker,portworx/docker,mtanlee/docker,AkihiroSuda/docker,tmp6154/docker,lixiaobing10051267/docker,shhsu/docker,lixiaobing10051267/docker,duglin/docker,trebonian/docker,jwhonce/docker,dgageot/docker,kolyshkin/moby,rhatdan/docker,catinthesky/docker,cpuguy83/docker,kunalkushwaha/docker,cyphar/docker,cyphar/docker,fcrisciani/docker,justincormack/docker,jlhawn/docker,tophj-ibm/moby,pradipd/moby,KarthikNayak/docker,afein/docker,ndeloof/docker,tonistiigi/docker,xiaods/docker,mike1729/docker,estesp/docker,msabansal/docker,portworx/docker,madhanrm/docker,tagomoris/docker,mtanlee/docker,nawawi/docker,harche/docker,naveed-jamil-tenpearls/moby,stevvooe/docker,johnstep/moby-moby,rremer/moby,icaoweiwei/docker,tklauser/docker,ripcurld0/moby,ajaymdesai/docker,gschaetz/moby,kojiromike/docker,dgageot/docker,jvanz/docker,trebonian/docker,mtrmac/docker,mikebrow/docker,bonczj/moby-json-file-logger,jlhawn/docker,cpuguy83/docker,yosifkit/docker,afein/docker,scotttlin/docker,rhatdan/docker,rremer/moby,erikh/docker,dims/docker,raja-sami-10p/moby,yasiramin10p/moby,jvanz/docker,flavio/docker,tianon/docker,Ramzec/docker,dims/docker,liaoqingwei/docker,ibuildthecloud/docker,whuwxl/docker,gnailuy/docker,mkumatag/docker,maxamillion/docker,noironetworks/docker,bearstech/moby,jlhawn/docker,erikh/docker,shishir-a412ed/docker,laijs/docker,yosifkit/docker,hqhq/moby,thaJeztah/docker,jthelin/docker,kojiromike/docker,asbjornenge/docker,HideoYamauchi/docker,michelvocks/docker,moypray/docker,dmcgowan/docker,darrenstahlmsft/docker,danyalKhaliq10p/moby,ColinHebert/docker,yummypeng/docker,sdurrheimer/docker,mohmost12/docker,bonczj/moby-json-file-logger,yummypeng/docker,imkin/moby,yummypeng/docker,yongtang/docker,coolljt0725/docker,ajaymdesai/docker,Ramzec/docker,tonistiigi/docker,rhatdan/docker,thaJeztah/docker,gschaetz/moby,diogomonica/docker,michael-holzheu/docker,KingEmet/docker,charleszheng44/moby,nalind/docker,icaoweiwei/docker,ibuildthecloud/docker,pramodhkp/moby,Mokolea/docker,mike1729/docker,amatsus/docker,POLJM242/docker,jameszhan/docker,dperny/docker,moul/docker,thaJeztah/docker,sfsmithcha/docker,ibuildthecloud/docker,konstruktoid/docker-upstream,ffoysal/docker,raja-sami-10p/moby,bearstech/moby,KingEmet/docker,laijs/moby,lixiaobing1/docker,lixiaobing1/docker,dccurtis/docker,AkihiroSuda/docker,sfsmithcha/docker,noironetworks/docker,ffoysal/docker,HuKeping/docker,nalind/docker,mtesselH/docker,konstruktoid/docker-upstream,michael-holzheu/docker,tophj-ibm/moby,laijs/moby,moby/moby,PatrickLang/moby,scotttlin/docker,crosbymichael/docker,kolyshkin/moby,moul/docker,harche/docker,q384566678/docker,thtanaka/docker,whuwxl/docker,thtanaka/docker,gjaskiewicz/moby,coolljt0725/docker,rancher/docker,ripcurld0/moby,kunalkushwaha/docker,sdurrheimer/docker,mixja/docker,konstruktoid/docker-upstream,prertik/docker,nalind/docker,vdemeester/docker,konstruktoid/docker-1,prertik/docker,moby/moby,duglin/docker,michelvocks/docker,prertik/docker,jameszhan/docker,haveatry/docker,djs55/docker,crosbymichael/docker,akira-baruah/docker,moul/docker,yosifkit/docker,YuPengZTE/docker,raja-sami-10p/moby,fcrisciani/docker,JMesser81/docker,srust/docker,SvenDowideit/docker,dperny/docker,mstanleyjones/docker,ajaymdesai/docker,mahak/docker,xiaods/docker,duglin/docker,akira-baruah/docker,docker/docker,endophage/docker,rremer/moby,sarnautov/moby,stevvooe/docker,lixiaobing10051267/docker,moul/docker,amatsus/docker,mtrmac/docker,ColinHebert/docker,estesp/docker,maxamillion/docker,ibuildthecloud/docker,shhsu/docker,shishir-a412ed/docker,mstanleyjones/docker,tklauser/docker,x1022as/docker,jthelin/docker,docker/docker,bearstech/moby,imkin/moby,mtesselH/docker,resin-io/docker,bonczj/moby-json-file-logger,x1022as/docker,mikedougherty/docker,dmcgowan/docker,catinthesky/docker,Ramzec/docker,coreos/docker,lixiaobing1/docker,jvanz/docker,mstanleyjones/docker,michael-holzheu/docker,alfred-landrum/docker,AkihiroSuda/docker,rancher/docker,allencloud/docker,darrenstahlmsft/docker,madhanrm/docker,tophj-ibm/docker,jimjag/docker,tagomoris/docker,kencochrane/docker,cpuguy83/docker,yasiramin10p/moby,coreos/docker,Syntaxide/docker,erikh/docker,dsheets/moby,gnailuy/docker,jimjag/docker,POLJM242/docker,imkin/moby,mahak/docker,johnstep/moby-moby,miminar/docker,mikedougherty/docker,sterchelen/docker,HideoYamauchi/docker,kencochrane/docker,konstruktoid/docker-upstream,kencochrane/docker,trebonian/docker,allencloud/docker,darrenstahlmsft/moby,msabansal/docker,qudongfang/docker,srust/docker,nawawi/docker,maxamillion/docker,haveatry/docker,tmp6154/docker,qudongfang/docker,splunk/docker,xuxinkun/docker,tophj-ibm/moby,asbjornenge/docker,JMesser81/docker,ibuildthecloud/docker,mtesselH/docker,jimjag/docker,mkumatag/docker,flavio/docker,erikstmartin/docker,cyphar/docker,sfsmithcha/docker,thtanaka/docker,dmcgowan/docker,scotttlin/docker,coreos/docker,haveatry/docker,Mokolea/docker,darrenstahlmsft/docker,miminar/docker,moby/moby,tianon/docker,shishir-a412ed/docker,ColinHebert/docker,estesp/docker,kolyshkin/moby,docker/docker,PatrickLang/moby,djs55/docker,gjaskiewicz/moby,YuPengZTE/docker,Mokolea/docker,mixja/docker,sdurrheimer/docker,KarthikNayak/docker,AkihiroSuda/docker,justincormack/docker,unclejack/docker,sterchelen/docker,endophage/docker,mike1729/docker,tonistiigi/docker,tagomoris/docker,madhanrm/docker,laijs/docker,mkumatag/docker,erikstmartin/docker,allencloud/docker,charleszheng44/moby,alfred-landrum/docker,miminar/docker,konstruktoid/docker-1,diogomonica/docker,dperny/docker,xiaods/docker,paralin/docker,mikebrow/docker,michelvocks/docker,amatsus/docker,yosifkit/docker,ffoysal/docker,ripcurld0/moby,yongtang/docker,jimjag/docker,pradipd/moby,moby/moby,tklauser/docker,jameszhan/docker,danyalKhaliq10p/moby,tophj-ibm/docker,afein/docker,HuKeping/docker,dsheets/moby,moypray/docker,mikebrow/docker,dccurtis/docker,KarthikNayak/docker,hqhq/moby,harche/docker,laijs/moby,srust/docker,nalind/docker,tophj-ibm/docker,Mokolea/docker,mohmost12/docker,alfred-landrum/docker,vdemeester/docker,jwhonce/docker,naveed-jamil-tenpearls/moby,Syntaxide/docker,Ramzec/docker,endophage/docker,fcrisciani/docker,vdemeester/docker,mahak/docker,jwhonce/docker,sarnautov/moby,laijs/docker,paralin/docker,pradipd/moby,kojiromike/docker,flavio/docker,PatrickLang/moby,mixja/docker,q384566678/docker,trebonian/docker,coolljt0725/docker,charleszheng44/moby,darrenstahlmsft/moby,diogomonica/docker,yasiramin10p/moby,pramodhkp/moby,kunalkushwaha/docker,SvenDowideit/docker,djs55/docker,gschaetz/moby,moypray/docker,naveed-jamil-tenpearls/moby,ndeloof/docker,rancher/docker,ndeloof/docker,splunk/docker,tmp6154/docker,dims/docker,Syntaxide/docker,gjaskiewicz/moby,whuwxl/docker,noironetworks/docker,JMesser81/docker,paralin/docker,flavio/docker,konstruktoid/docker-1,YuPengZTE/docker,mohmost12/docker,yongtang/docker,cpuguy83/docker,paralin/docker,pramodhkp/moby,dsheets/moby