Commit a2cd66be8a7a0da65a197eef69c4dadc9ecf7f49

Nicolas Cavallari 2021-06-23T16:57:48

docs: stop mentioning libgit2's "master" branch The name of libgit2's main branch is now "main" but contributing.md and release.md still reference "master" as the main branch. Fix it.