Clarification: any purpose for master branch?

I see that the `asf-site` branch is both the default branch and what the TeamCity CI job tracks. The `master` branch is currently far behind (but not an actual ancestor of) `asf-site`.

I might be the only person that this ever confuses, but is there a positive reason for `master` to exist or does it make sense to just delete it?

Start by checking the repository's branch configuration and the TeamCity CI job that tracks asf-site. Compare master with asf-site and review the six existing comments for any stated purpose or dependency. Done means recording a maintainer-backed decision about master and documenting or carrying out the resulting repository change.

Written by the indexing model from the issue text.