Linking to About page from the header
Linking to About page from the header

We were missing a link to the about page when already logged in. While
this is non-obvious, it'd be good if it acts as a "Help".

Also added an "About" link on the right of the navbar, it should help
guide users while keeping the UI uncluttered.

ricardojmendez/memento,ricardojmendez/memento,ricardojmendez/memento