Add common footer with a Github icon and link to this repo

[shanzzam]

What problem does your feature solve?

Better visibility to code and a way for users to provide feedback, log bugs, and submit changes themselves.

What would you like to see?

A footer added to the mainpage with the Github icon and link to the Issues or Main page of this repo

What alternatives are there?

We can keep the announcement banner at the top of the page for a bit but other than that there isn't an easy way to discover this repo.

[shanzzam]

Text on the footer: "Check out our Github repo more information and to log issues"
That may be too wordy @lydiat

[quietbits]

@shanzzam @lydiat We could show a longer description on hover.

P.S. I will add the GitHub icon once we've finalized the link text.

[lydiat]

[quietbits]

More links added in #171

[shanzzam]

@quietbits looks good! I've reviewed and will close this as complete.