Update migration documentation
Update migration documentation

Soullivaneuh/gitlabhq,ferdinandrosario/gitlabhq,ferdinandrosario/gitlabhq,sue445/gitlabhq,cui-liqiang/gitlab-ce,dwrensha/gitlabhq,openwide-java/gitlabhq,cui-liqiang/gitlab-ce,louahola/gitlabhq,ferdinandrosario/gitlabhq,duduribeiro/gitlabhq,Soullivaneuh/gitlabhq,larryli/gitlabhq,mr-dxdy/gitlabhq,Datacom/gitlabhq,dplarson/gitlabhq,szechyjs/gitlabhq,fpgentil/gitlabhq,dplarson/gitlabhq,yatish27/gitlabhq,SVArago/gitlabhq,ksoichiro/gitlabhq,axilleas/gitlabhq,dwrensha/gitlabhq,icedwater/gitlabhq,SVArago/gitlabhq,fpgentil/gitlabhq,mmkassem/gitlabhq,dreampet/gitlab,axilleas/gitlabhq,louahola/gitlabhq,daiyu/gitlab-zh,MauriceMohlek/gitlabhq,koreamic/gitlabhq,stoplightio/gitlabhq,icedwater/gitlabhq,screenpages/gitlabhq,sue445/gitlabhq,martijnvermaat/gitlabhq,allysonbarros/gitlabhq,LUMC/gitlabhq,t-zuehlsdorff/gitlabhq,sonalkr132/gitlabhq,daiyu/gitlab-zh,jrjang/gitlabhq,mr-dxdy/gitlabhq,stoplightio/gitlabhq,sonalkr132/gitlabhq,mrb/gitlabhq,htve/GitlabForChinese,koreamic/gitlabhq,cui-liqiang/gitlab-ce,jrjang/gitlabhq,ksoichiro/gitlabhq,szechyjs/gitlabhq,openwide-java/gitlabhq,dwrensha/gitlabhq,mrb/gitlabhq,shinexiao/gitlabhq,darkrasid/gitlabhq,iiet/iiet-git,SVArago/gitlabhq,dplarson/gitlabhq,mr-dxdy/gitlabhq,mrb/gitlabhq,icedwater/gitlabhq,ikappas/gitlabhq,martijnvermaat/gitlabhq,darkrasid/gitlabhq,yatish27/gitlabhq,szechyjs/gitlabhq,Telekom-PD/gitlabhq,yatish27/gitlabhq,screenpages/gitlabhq,mrb/gitlabhq,dreampet/gitlab,louahola/gitlabhq,mmkassem/gitlabhq,axilleas/gitlabhq,openwide-java/gitlabhq,mmkassem/gitlabhq,Soullivaneuh/gitlabhq,jirutka/gitlabhq,martijnvermaat/gitlabhq,LUMC/gitlabhq,allysonbarros/gitlabhq,shinexiao/gitlabhq,sue445/gitlabhq,ikappas/gitlabhq,koreamic/gitlabhq,duduribeiro/gitlabhq,dreampet/gitlab,ksoichiro/gitlabhq,LUMC/gitlabhq,stoplightio/gitlabhq,gopeter/gitlabhq,ttasanen/gitlabhq,openwide-java/gitlabhq,jrjang/gitlab-ce,iiet/iiet-git,allysonbarros/gitlabhq,iiet/iiet-git,darkrasid/gitlabhq,jrjang/gitlabhq,shinexiao/gitlabhq,sonalkr132/gitlabhq,Telekom-PD/gitlabhq,szechyjs/gitlabhq,louahola/gitlabhq,jrjang/gitlab-ce,mr-dxdy/gitlabhq,jirutka/gitlabhq,martijnvermaat/gitlabhq,dwrensha/gitlabhq,jrjang/gitlabhq,SVArago/gitlabhq,jrjang/gitlab-ce,dreampet/gitlab,Telekom-PD/gitlabhq,ttasanen/gitlabhq,ttasanen/gitlabhq,Datacom/gitlabhq,jirutka/gitlabhq,daiyu/gitlab-zh,MauriceMohlek/gitlabhq,screenpages/gitlabhq,gopeter/gitlabhq,cui-liqiang/gitlab-ce,jirutka/gitlabhq,htve/GitlabForChinese,gopeter/gitlabhq,Telekom-PD/gitlabhq,duduribeiro/gitlabhq,jrjang/gitlab-ce,mmkassem/gitlabhq,duduribeiro/gitlabhq,larryli/gitlabhq,sue445/gitlabhq,allysonbarros/gitlabhq,ikappas/gitlabhq,MauriceMohlek/gitlabhq,sonalkr132/gitlabhq,ikappas/gitlabhq,axilleas/gitlabhq,t-zuehlsdorff/gitlabhq,screenpages/gitlabhq,t-zuehlsdorff/gitlabhq,ferdinandrosario/gitlabhq,LUMC/gitlabhq,yatish27/gitlabhq,stoplightio/gitlabhq,Soullivaneuh/gitlabhq,fpgentil/gitlabhq,larryli/gitlabhq,dplarson/gitlabhq,shinexiao/gitlabhq,koreamic/gitlabhq,ksoichiro/gitlabhq,larryli/gitlabhq,htve/GitlabForChinese,iiet/iiet-git,ttasanen/gitlabhq,icedwater/gitlabhq,fpgentil/gitlabhq,MauriceMohlek/gitlabhq,darkrasid/gitlabhq,htve/GitlabForChinese,Datacom/gitlabhq,t-zuehlsdorff/gitlabhq,daiyu/gitlab-zh,Datacom/gitlabhq,gopeter/gitlabhq