Mastodon icon for contacts links

[MrGreensWorkshop]

Is this enhancement or feature is related to a problem?

I think it's better to have the mastodon icon for the contact option.

Describe the solution you'd like

Since the mastodon icon is not available in Font Awesome 4.7.0, I added an svg file for it.

The mastodon icon was obtained from mastodon repo

Describe alternatives you've considered

none

Additional context

none

[MrGreensWorkshop]

This is how it looks after adding the icon.