front page (org index) should be more dashboard-like

[mpdehaan]

The front page of the app ("/") currently lists the organizations, but there's a lot of free space which could be WAY more impressive looking, with most of the good content happening 1 screen away.

it would be nice to list stats about how much is in the system ... total number of repos managed, total number of authors, repos with most recent changes (maybe), repos with most recent scans, etc.

There's some freedom in what this might be, but the idea is to make the dashboard a bit more compelling for demos, where as right now it's mostly blank.

It could probably also use the image of the logo as a watermark or something more creative, TBD.