docs: Update release checklist to mention GitHub.
docs: Update release checklist to mention GitHub.

dawran6/zulip,tommyip/zulip,christi3k/zulip,vabs22/zulip,j831/zulip,rht/zulip,zulip/zulip,vaidap/zulip,synicalsyntax/zulip,PhilSk/zulip,shubhamdhama/zulip,dattatreya303/zulip,amanharitsh123/zulip,showell/zulip,verma-varsha/zulip,christi3k/zulip,zulip/zulip,brockwhittaker/zulip,kou/zulip,jackrzhang/zulip,eeshangarg/zulip,showell/zulip,rht/zulip,punchagan/zulip,SmartPeople/zulip,JPJPJPOPOP/zulip,rishig/zulip,kou/zulip,vaidap/zulip,j831/zulip,mahim97/zulip,punchagan/zulip,sonali0901/zulip,jphilipsen05/zulip,aakash-cr7/zulip,zulip/zulip,andersk/zulip,SmartPeople/zulip,jainayush975/zulip,timabbott/zulip,blaze225/zulip,vabs22/zulip,dattatreya303/zulip,tommyip/zulip,showell/zulip,shubhamdhama/zulip,dawran6/zulip,sonali0901/zulip,kou/zulip,jackrzhang/zulip,aakash-cr7/zulip,christi3k/zulip,eeshangarg/zulip,hackerkid/zulip,vaidap/zulip,brockwhittaker/zulip,timabbott/zulip,vaidap/zulip,aakash-cr7/zulip,susansls/zulip,dhcrzf/zulip,punchagan/zulip,punchagan/zulip,brockwhittaker/zulip,dawran6/zulip,susansls/zulip,j831/zulip,showell/zulip,ryanbackman/zulip,samatdav/zulip,showell/zulip,jrowan/zulip,jainayush975/zulip,jphilipsen05/zulip,timabbott/zulip,jrowan/zulip,eeshangarg/zulip,dhcrzf/zulip,susansls/zulip,hackerkid/zulip,rht/zulip,dattatreya303/zulip,jphilipsen05/zulip,hackerkid/zulip,mahim97/zulip,amanharitsh123/zulip,brainwane/zulip,brainwane/zulip,shubhamdhama/zulip,blaze225/zulip,jainayush975/zulip,sonali0901/zulip,Galexrt/zulip,verma-varsha/zulip,jackrzhang/zulip,dawran6/zulip,timabbott/zulip,ryanbackman/zulip,andersk/zulip,JPJPJPOPOP/zulip,Galexrt/zulip,jphilipsen05/zulip,Galexrt/zulip,rht/zulip,zulip/zulip,amanharitsh123/zulip,Galexrt/zulip,jrowan/zulip,dhcrzf/zulip,dawran6/zulip,timabbott/zulip,vaidap/zulip,brainwane/zulip,vabs22/zulip,sonali0901/zulip,jainayush975/zulip,andersk/zulip,showell/zulip,susansls/zulip,amanharitsh123/zulip,ryanbackman/zulip,eeshangarg/zulip,souravbadami/zulip,punchagan/zulip,brainwane/zulip,susansls/zulip,souravbadami/zulip,brainwane/zulip,verma-varsha/zulip,samatdav/zulip,blaze225/zulip,PhilSk/zulip,SmartPeople/zulip,brainwane/zulip,rht/zulip,souravbadami/zulip,brockwhittaker/zulip,hackerkid/zulip,synicalsyntax/zulip,zulip/zulip,amanharitsh123/zulip,timabbott/zulip,timabbott/zulip,dawran6/zulip,samatdav/zulip,dattatreya303/zulip,jrowan/zulip,zulip/zulip,jainayush975/zulip,ryanbackman/zulip,rht/zulip,christi3k/zulip,tommyip/zulip,PhilSk/zulip,rishig/zulip,samatdav/zulip,vabs22/zulip,andersk/zulip,Galexrt/zulip,andersk/zulip,vabs22/zulip,rishig/zulip,dhcrzf/zulip,verma-varsha/zulip,JPJPJPOPOP/zulip,jrowan/zulip,hackerkid/zulip,shubhamdhama/zulip,eeshangarg/zulip,sonali0901/zulip,tommyip/zulip,vabs22/zulip,christi3k/zulip,synicalsyntax/zulip,jphilipsen05/zulip,aakash-cr7/zulip,mahim97/zulip,vaidap/zulip,andersk/zulip,eeshangarg/zulip,punchagan/zulip,showell/zulip,PhilSk/zulip,jphilipsen05/zulip,tommyip/zulip,JPJPJPOPOP/zulip,SmartPeople/zulip,dhcrzf/zulip,rht/zulip,j831/zulip,mahim97/zulip,hackerkid/zulip,samatdav/zulip,blaze225/zulip,amanharitsh123/zulip,sonali0901/zulip,blaze225/zulip,jackrzhang/zulip,rishig/zulip,PhilSk/zulip,rishig/zulip,zulip/zulip,jackrzhang/zulip,verma-varsha/zulip,ryanbackman/zulip,brainwane/zulip,dhcrzf/zulip,aakash-cr7/zulip,JPJPJPOPOP/zulip,shubhamdhama/zulip,Galexrt/zulip,punchagan/zulip,souravbadami/zulip,brockwhittaker/zulip,Galexrt/zulip,susansls/zulip,synicalsyntax/zulip,j831/zulip,JPJPJPOPOP/zulip,dattatreya303/zulip,mahim97/zulip,verma-varsha/zulip,jainayush975/zulip,SmartPeople/zulip,christi3k/zulip,aakash-cr7/zulip,tommyip/zulip,synicalsyntax/zulip,jackrzhang/zulip,blaze225/zulip,synicalsyntax/zulip,ryanbackman/zulip,tommyip/zulip,jackrzhang/zulip,synicalsyntax/zulip,kou/zulip,andersk/zulip,shubhamdhama/zulip,brockwhittaker/zulip,PhilSk/zulip,eeshangarg/zulip,j831/zulip,souravbadami/zulip,hackerkid/zulip,shubhamdhama/zulip,souravbadami/zulip,dattatreya303/zulip,rishig/zulip,rishig/zulip,samatdav/zulip,jrowan/zulip,mahim97/zulip,kou/zulip,kou/zulip,SmartPeople/zulip,kou/zulip,dhcrzf/zulip