Add Tor Messenger to volunteer page
This patch adds Tor Messenger to the volunteer page. I am not clear about the order the projects follow so I just put it up before TorBirdy. If that is not fine, please let me know the correct order and I will update the patch.
Additionally, this patch updates the link to TorBirdy from GitHub to gitweb.torproject.org.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information