Symlinks don't work quite right

Symbolic links can be viewed and followed perfectly fine on the keybase file browser. An example can be seen [here](https://keybase.pub/benburrill/), where I symlink `/keybase/public/benburrill/src/style/` to `/keybase/public/benburrill/style/`. However, you get a 404 if you try to access `/style/rst.css` directly. This results in https://benburrill.keybase.pub/ not being styled appropriately because it links to `/style/rst.css`.

Start by reproducing the linked symlink example and the direct /style/rst.css request, then inspect the public file-serving path used by the Keybase file browser. Done means a symlinked stylesheet URL resolves successfully instead of returning 404, so the linked site is styled correctly.

Written by the indexing model from the issue text.