[ci skip] Update config/migration.php comments
[ci skip] Update config/migration.php comments

Close #3951

shrimpma/CodeIgniter,marimarluna/CodeIgniter-develop,kukuhsetiawan/CodeIgniter,runphp/CodeIgniter,Neoskate/CodeIgniter,galdiolo/CodeIgniter,bcit-ci/CodeIgniter,titounnes/CI_BaseConfig,it-can/CodeIgniter,ganiutomo/CodeIgniter,serpes/CodeIgniter,tianhe1986/CodeIgniter,ivantcholakov/CodeIgniter,pkdevbox/CodeIgniter,Gektorian/CodeIgniter,benms/CodeIgniter,nandadotexe/CodeIgniter,marimarluna/CodeIgniter-develop,LamarKing/CodeIgniter,lonnieezell/CodeIgniter,rajrathore/CodeIgniter,kamaslau/BasicCodeIgniter,dcarbone/CodeIgniter,kobeuu/CodeIgniter,DavidOtis/CodeIgniter,cgvarela/CodeIgniter,juanjosemiranda/primer,Calico90/CodeIgniter,dotancohen/CodeIgniter,ET-NiK/CodeIgniter,eddomirsyad/CodeIgniter,globlob/CodeIgniter,it-can/CodeIgniter,eddomirsyad/CodeIgniter,bcit-ci/CodeIgniter,tangposmarvin/CodeIgniter,kenjis/CodeIgniter,kuaimainc/Kuaima-CodeIgniter,eddomirsyad/CodeIgniter,madnik/CodeIgniter,daoyuly/CodeIgniter,CodeIgniter-Chinese/CodeIgniter,nadeemehsan9/CodeIgniter,KeiroD/CodeIgniter,ytetsuro/CodeIgniter,dotancohen/CodeIgniter,demenvil/CodeIgniter,r-cis/CodeIgniter,pkuclay/CodeIgniter,HindrikDeelstra/codeigniter-snackapp,natepizzle/nah-codeigniter,gastongr/CodeIgniter,ytetsuro/CodeIgniter,jim-parry/CodeIgniter,tianhe1986/CodeIgniter,HindrikDeelstra/codeigniter-snackapp,pkdevbox/CodeIgniter,skullJ/CodeIgniter,cgvarela/CodeIgniter,joariasl/CodeIgniter,gt945/CodeIgniter,ftwbzhao/CodeIgniter,Calico90/CodeIgniter,JungMinu/CodeIgniter,whilewon/CodeIgniter,mewt/CodeIgniter,Sevdr/CodeIgniter,nonconforme/CodeIgniter,benms/CodeIgniter,pravinhirmukhe/CodeIgniter,kigsmtua/CodeIgniter,roastduck/CodeIgniter,zhanghongyi/CodeIgniter,Brother-Simon/CodeIgniter,Oiro/CodeIgniter,neomadara/CodeIgniter,mfaraz/CodeIgniter,darrelljefferson/viper,namnv609/CodeIgniter,titounnes/CodeIgniter,Tpojka/CodeIgniter,jiachenning/CodeIgniter,yonineitor/CodeIgniter,Bluewind/filebin,pkdevbox/CodeIgniter,ipabz/CodeIgniter,asmdigital/CodeIgniter,Gektorian/CodeIgniter,Brother-Simon/CodeIgniter,WSDC-NITWarangal/CodeIgniter,mfaraz/CodeIgniter,chinatown34/ci_bind_wrap,marimarluna/CodeIgniter-develop,dkarvounaris/CodeIgniter,vrkansagara/CodeIgniter,asmdigital/CodeIgniter,serpes/CodeIgniter,whilewon/CodeIgniter,darrelljefferson/viper,moon-siama/codeigniter,aperera/CodeIgniter,kenjis/CodeIgniter,KmServer/CodeIgniter,r-cis/CodeIgniter,openset/ci,FacundoGFlores/CodeIgniter,ajose1024/Code_Igniter_Extended,WSDC-NITWarangal/CodeIgniter,kuaimainc/Kuaima-CodeIgniter,pravinhirmukhe/CodeIgniter,fjsevillamora/CodeIgniter,ivantcholakov/CodeIgniter,moon-siama/codeigniter,LamarKing/CodeIgniter,namnv609/CodeIgniter,openset/ci,shanavas786/CodeIgniter,faregon/CodeIgniter,Neoskate/CodeIgniter,iLotus/CodeIgniter,HindrikDeelstra/codeigniter-snackapp,jiachenning/CodeIgniter,aquasky111/CodeIgniter,liuxulei/CodeIgniter,freeztime/CodeIgniter,moon-siama/codeigniter,DiederikLascaris/CodeIgniter,dinhmv/demo,Bluewind/filebin,nadeemehsan9/CodeIgniter,feryardiant/codeigniter,Husseinat/engsoft,n054/CodeIgniter,chadzilla2080/CodeIgniter,joariasl/CodeIgniter,antoniors/CodeIgniter,weslenam/kymera,mewt/CodeIgniter,shrimpma/CodeIgniter,freeztime/CodeIgniter,dinhmv/demo,ganiutomo/CodeIgniter,daoyuly/CodeIgniter,KIGOTHO/CodeIgniter,nandadotexe/CodeIgniter,chinatown34/ci_bind_wrap,marimarluna/CodeIgniter-develop,demenvil/CodeIgniter,natepizzle/nah-codeigniter,r-cis/CodeIgniter,taro-asahi/CodeIgniter,andersonunsonst/CodeIgniter,TimHuangcheng/CodeIgniter,Cediwallet/code,joariasl/CodeIgniter,MjAbuz/CodeIgniter,weslenam/kymera,aquasky111/CodeIgniter,faregon/CodeIgniter,KIGOTHO/CodeIgniter,Oiro/CodeIgniter,MonCoder/CodeIgniter,fjsevillamora/CodeIgniter,ster/CodeIgniter,gopalindians/CodeIgniter,asmdigital/CodeIgniter,cgvarela/CodeIgniter,rootcss/CodeIgniter,sebastienadam/CodeIgniter,alex1442/CodeIgniter,kigsmtua/CodeIgniter,dcarbone/CodeIgniter,gastongr/CodeIgniter,MjAbuz/CodeIgniter,netsan/CodeIgniter-Research,andreaslangsays/CodeIgniter,pkuclay/CodeIgniter,HindrikDeelstra/codeigniter-snackapp,shanavas786/CodeIgniter,zoaked/CodeIgniter,aquasky111/CodeIgniter,puhua/CodeIgniter,iLotus/CodeIgniter,kobeuu/CodeIgniter,dinhmv/demo,zhaoyan158567/CodeIgniter,fjsevillamora/CodeIgniter,alex1442/CodeIgniter,globlob/CodeIgniter,Gektorian/CodeIgniter,faregon/CodeIgniter,megaspy/rental,poing/CodeIgniter,acepsaepudin/traffic-infrastructure-app,kala725/CodeIgniter-with-React,it-can/CodeIgniter,taro-asahi/CodeIgniter,tangposmarvin/CodeIgniter,smallp/CodeIgniter,joel-medeiros/CodeIgniter,aquasky111/CodeIgniter,jellycheng/CodeIgniter,n054/CodeIgniter,juanjosemiranda/primer,souparno/CodeIgniter,ShrmnK/CodeIgniter,faregon/CodeIgniter,feryardiant/codeigniter,zhangzhengyu/CodeIgniter,alex1442/CodeIgniter,ipabz/CodeIgniter,ytetsuro/CodeIgniter,Brother-Simon/CodeIgniter,pkuclay/CodeIgniter,asmdigital/CodeIgniter,TimHuangcheng/CodeIgniter,tschmidiger/CodeIgniter,zhaoyan158567/CodeIgniter,megaspy/rental,cmayo/CodeIgniter,juanjosemiranda/primer,ster/CodeIgniter,runphp/CodeIgniter,dhayalram123/CodeIgniter,avenirer/CodeIgniter,ap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er,souparno/CodeIgniter,Cediwallet/code,openset/ci,jellycheng/CodeIgniter,DiZyStudio/ci,lonnieezell/CodeIgniter,avenirer/CodeIgniter,yonineitor/CodeIgniter,cmayo/CodeIgniter,ster/CodeIgniter,pravinhirmukhe/CodeIgniter,rafelsanso/kitmaker-project,tianhe1986/CodeIgniter,tschmidiger/CodeIgniter,ShrmnK/CodeIgniter,nadeemehsan9/CodeIgniter,gastongr/CodeIgniter,gastongr/CodeIgniter,kobeuu/CodeIgniter,tschmidiger/CodeIgniter,Calico90/CodeIgniter,joariasl/CodeIgniter,tianhe1986/CodeIgniter,KmServer/CodeIgniter,puhua/CodeIgniter,CodeIgniter-Chinese/CodeIgniter,Bluewind/filebin,zhaoyan158567/CodeIgniter,runphp/CodeIgniter,taro-asahi/CodeIgniter,avenirer/CodeIgniter,vrkansagara/CodeIgniter,DiZyStudio/ci,Husseinat/engsoft,roastduck/CodeIgniter,bcit-ci/CodeIgniter,dkarvounaris/CodeIgniter,pkuclay/CodeIgniter,zoaked/CodeIgniter,trinet-at/CodeIgniter,JungMinu/CodeIgniter,souparno/CodeIgniter,chinatown34/ci_bind_wrap,DiZyStudio/ci,zcodes/CodeIgniter,darrelljefferson/viper,AndreiMariusSili/Enactus,MjAbuz/CodeIgniter,Bluewind/filebin,jim-parry/CodeIgniter,benms/CodeIgniter,marimarluna/CodeIgniter-develop,dotancohen/CodeIgniter,zhangbo127/CodeIgniter,trinet-at/CodeIgniter,dhayalram123/CodeIgniter,b1tc0re/CodeIgniter,joel-medeiros/CodeIgniter,shrimpma/CodeIgniter,MonCoder/CodeIgniter,poing/CodeIgniter,cmayo/CodeIgniter,KeiroD/CodeIgniter,ajose1024/Code_Igniter_Extended,TimHuangcheng/CodeIgniter,feryardiant/codeigniter,lucasfong/CodeIgniter,ivantcholakov/CodeIgniter,Avantians/CodeIgniter,nishatbaig/CodeIgniter,serpes/CodeIgniter,vrkansagara/CodeIgniter,kenjis/CodeIgniter,r-cis/CodeIgniter,aryan-2016/CodeIgniter,kala725/CodeIgniter-with-React,saisai/CodeIgniter,TimHuangcheng/CodeIgniter,tieutumathi/CodeIgniterM,MjAbuz/CodeIgniter,AndreiMariusSili/EnactusMVC,globlob/CodeIgniter,kukuhsetiawan/CodeIgniter,usbader/QuizApp,saisai/CodeIgniter,tschmidiger/CodeIgniter,Tpojka/CodeIgniter,mfaraz/CodeIgniter,Neoskate/CodeIgniter,Sproypef/CodeIgniter_AdminLTE2_Blade,titounnes/CodeIgniter,gopalindians/CodeIgniter,asmdigital/CodeIgniter,dkarvounaris/CodeIgniter,kukuhsetiawan/CodeIgniter,invitecomm/CodeIgniter,KeiroD/CodeIgniter,nonconforme/CodeIgniter,ivantcholakov/CodeIgniter,Avantians/CodeIgniter,Sproypef/CodeIgniter_AdminLTE2_Blade,kenjis/CodeIgniter,ganiutomo/CodeIgniter,puhua/CodeIgniter,Avantians/CodeIgniter,FacundoGFlores/CodeIgniter,gt945/CodeIgniter,zcodes/CodeIgniter,madwings/InsaneDB,kuaimainc/Kuaima-CodeIgniter,sebastienadam/CodeIgniter,ajose1024/Code_Igniter_Extended,FacundoGFlores/CodeIgniter,jiaojie1989/CodeIgniter,HindrikDeelstra/codeigniter-snackapp,zhangzhengyu/CodeIgniter,nadeemehsan9/CodeIgniter,ipabz/CodeIgniter,faozimipa/CodeIgniter,Husseinat/engsoft,lucasfong/CodeIgniter,galdiolo/CodeIgniter,nishatbaig/CodeIgniter,souparno/CodeIgniter,Sevdr/CodeIgniter,mewt/CodeIgniter,saisai/CodeIgniter,DiederikLascaris/CodeIgniter,Brother-Simon/CodeIgniter,shrimpma/CodeIgniter,FacundoGFlores/CodeIgniter,neomadara/CodeIgniter,stevebritton/CodeIgniter,aperera/CodeIgniter,kamaslau/BasicCodeIgniter,Tpojka/CodeIgniter,iLotus/CodeIgniter,zhanghongyi/CodeIgniter,zhanghongyi/CodeIgniter,darrelljefferson/viper,Husseinat/engsoft,AndreiMariusSili/EnactusMVC,chinatown34/ci_bind_wrap,daoyuly/CodeIgniter,lonnieezell/CodeIgniter,whilewon/CodeIgniter,zhangbo127/CodeIgniter,trinet-at/CodeIgniter,openset/ci,ShrmnK/CodeIgniter,Tpojka/CodeIgniter,shanavas786/CodeIgniter,feryardiant/codeigniter,DiZyStudio/ci,skullJ/CodeIgniter,SmileDrug/CodeIgniter,aryan-2016/CodeIgniter,jellycheng/CodeIgniter,Tpojka/CodeIgniter,sebastienadam/CodeIgniter,tianhe1986/CodeIgniter,madnik/CodeIgniter,kala725/CodeIgniter-with-React,b1tc0re/CodeIgniter,megaspy/rental,zares85/mvf,dotancohen/CodeIgniter,dimaspermadiyp/CodeIgniter,liuxulei/CodeIgniter,nonconforme/CodeIgniter,invitecomm/CodeIgniter,dcarbone/CodeIgniter,JungMinu/CodeIgniter,Neoskate/CodeIgniter,MonCoder/CodeIgniter,zhangzhengyu/CodeIgniter,ipabz/CodeIgniter,dhayalram123/CodeIgniter,kobeuu/CodeIgniter,jim-parry/CodeIgniter,rajrathore/CodeIgniter,KmServer/CodeIgniter,liuxulei/CodeIgniter,kala725/CodeIgniter-with-React,asp7bit/trackindo,ivantcholakov/CodeIgniter,invitecomm/CodeIgniter,n054/CodeIgniter,ganiutomo/CodeIgniter,poing/CodeIgniter,madwings/InsaneDB,MonCoder/CodeIgniter,CodeIgniter-Chinese/CodeIgniter,bcit-ci/CodeIgniter,zhangbo127/CodeIgniter,zoaked/CodeIgniter,dimaspermadiyp/CodeIgniter,nishatbaig/CodeIgniter,usbader/QuizApp,namnv609/CodeIgniter,kukuhsetiawan/CodeIgniter,KIGOTHO/CodeIgniter,andersonunsonst/CodeIgniter,joel-medeiros/CodeIgniter,titounnes/CI_BaseConfig,gopalindians/CodeIgniter,DavidOtis/CodeIgniter,dcarbone/CodeIgniter