Merge pull request #6500 from timrogers/timrogers/empty-docs

Correct the definition of "empty" in the docs for `git_repository_is_empty`

include/git2/repository.h

@@ -465,7 +465,9 @@ GIT_EXTERN(int) git_repository_head_unborn(git_repository *repo);
  * Check if a repository is empty
  *
  * An empty repository has just been initialized and contains no references
- * apart from HEAD, which must be pointing to the unborn master branch.
+ * apart from HEAD, which must be pointing to the unborn master branch,
+ * or the branch specified for the repository in the `init.defaultBranch`
+ * configuration variable.
  *
  * @param repo Repo to test
  * @return 1 if the repository is empty, 0 if it isn't, error code