Add Linux mint in download options
Linux mint is one of the most popular distributions.
It's based on Ubuntu and since we use it, Ring on Mint is almost as tested as on Ubuntu.
Yet, the Linux mint user will still struggle through a few annoying step to download Ring.
- The user most know that Mint is based on Ubuntu
- Check such a table: https://fr.wikipedia.org/wiki/Linux_Mint#Tableau_des_versions
A simple indication such as "Ubuntu 16.04 (Linux Mint 18-18.3)" and "Ubuntu 18.04 (Linux Mint 19)" or new dedicated shortcut entries would help all Mint user.