The branch names are whatever you want them to be. While a lot of developers use master or main, it can be whatever you want, there is no fixed requirements.
It all comes down if you want to try to follow a strict git methodology (like git flow) or just roll your own. It seems most Ignition workflows don’t follow exactly an existing git methodology, for our devops we only use develop and master branches and have a repo for each project, but have not yet matured to having feature or hotfix branches. Basically develop branch is always what is checked out in our DEV environment, when developer is ready they use perspective to commit the project on the gateway and push to azure. If they want to then release the project to TEST or Production, they open a Pull request that triggers deployments for the TEST environment and when the PR is closed and merged to master, the master branch is deployed to Production.