You do have to include it on build, but when you add the custom domain from the github site it automatically creates and commits the CNAME file for you.
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
You don't need to create the CNAME file by hand, GitHub does that automatically, when you enter the custom domain in the repository settings.
Cool! I was having a problem that if I didn't include CNAME on build, this setting would reset after each deploy.
You do have to include it on build, but when you add the custom domain from the github site it automatically creates and commits the CNAME file for you.