add documentation for deprecating master

[andreeaflorescu]

GitHub changed the default branch name to main. We should also follow the example and rename the existing branches. As there are consumers of rust-vmm that use the master branch in their products, we need to mark it as deprecated instead of simply renaming it to main.

[rbradford]

If you use the UI for renaming a branch the GitHub will redirect pending PRs, redirect URLs, etc so will give a better experience than doing it manually.

[andreeaflorescu]

@rbradford that was my initial thought as well, but then when we discussed about this in the sync meeting @sboeuf suggested we keep both because you are consuming the master branch, and that might break your (or other customers) build.

If that is not the case, I more than happy to just rename the branch. That also comes with the advantage that I don't have to manually add PRs to all rust-vmm repositories to deprecate master, because master would no longer exist.

[rbradford]

@rbradford that was my initial thought as well, but then when we discussed about this in the sync meeting @sboeuf suggested we keep both because you are consuming the master branch, and that might break your (or other customers) build.

@sboeuf When you made that comment about keeping the branch were you aware of the GitHub redirect behaviour when you rename a branch?

[sboeuf]

@sboeuf When you made that comment about keeping the branch were you aware of the GitHub redirect behaviour when you rename a branch?

No I wasn't. So I definitely think we can go ahead and remove master.

[andreeaflorescu]

Awesome :confetti_ball: I'll just then go ahead and rename all branches. This will also help with the CI, as keeping both master and main working is a bit challenging at the moment. Closing this.