Create a git repository for https://aus1.torproject.org/torbrowser/

Since we only host small files on https://aus1.torproject.org/torbrowser/, I think it could be stored in a git repository.

It mostly contains files auto-generated, but sometimes we need to tweak some .htaccess files, which would be useful to have in a git repository. Being able to look at the history of update files would be nice too.

If we do that, when we publish a new version, instead of copying the updates files to staticiforme.torproject.org and running static-update-component aus1.torproject.org, we'll need to commit them to a git repository before checking out the commit on staticiforme.torproject.org and running static-update-component aus1.torproject.org.

/cc @richard