Settings page should link to Amber Dashboard

[jerclarke]

This article is very useful: https://github.com/berkmancenter/amber_wordpress/wiki/Default

But without reading it, it's a lot harder for a user to figure out Amber. We found the settings page on our own, but didn't realize the dashboard was there 'till reading all the docs. Would be very useful to have a link from settings to dashbard and back again for users to quickly find the various tools.