Contribution leader board page

[SKairinos]

(Nice to have)

Create a page on the front end to display the leader board.

If the the users content has enabled their contact info to be public, hovering over each username in the leader board should show their full name and latest email.

This page should be the landing page of the service.

[lauracumming]

I think we should take this out of this epic and create a new epic from it.