Consider some "top level" stats/metrics to display in `/repos` page?

[patrickdevivo]

Above the main repos table, maybe some things like:

• Total number of repos (that match the current filters - tags and search terms)
• Avg. number of syncs per repo
• Avg. sync run time

etc. Basically some numbers (maybe small charts?) to give the user an aggregate sense of what their repo and sync data looks like