[tor-relays] Marker branch for current tor release(s)

Hi everybody,

https://www.torproject.org/download/download.html.en in the source code 'tab' states the current stable and alpha version of tor.

Would it be possible to publish the current states as branches 'stable' and 'alpha' (or 'testing', or 'unstable') in the git repo?

That would help us tor-from-source builders to just fetch the repo, and if the respective branch changes, to rebuild and redeploy. Looking for a new release tag or screen-scraping said web page is a bit hairy, and feels unnecessary.

- Andreas