Could we add a prefix option to [git-annex-export](https://git-annex.branchable.com/git-annex-export/)?
Something like `git annex export master:some-videos --to myexport --prefix share-with-john` would create a new subdirectory called `share-with-john` on the `myexport` exporttree remote and copy all files from the local `some-videos` directory into the new `share-with-john` directory.
I could then do another export using the same remote like `git annex export master:some-other-videos --to myexport --prefix share-with-bill` which wouldn't touch any of the videos I previously shared with john but would create a new export into a new `share-with-bill` directory.
My goal with the prefix option is to setup an exporttree remote one time, but then be able to re-use this same remote multiple times to create independent publicly shared folders.
