Incorporate more activity into homepage feed

[themightychris]

• New members (maybe chunked together)
• New projects (maybe chunked together)
• Concluded meetups with a list of all who checked in

This should probably start as a wireframe that explores how to lay all this out with the existing content cleanly. It might be cool to include or preview commenting on some or all of these items right from the feed.

[schlos]

+1

New members could be welcomed to the brigade by grouping into one post weekly, e.g. triggered every friday: "Please give warm welcome to new members Name1, Name2, Name3!"

New projects could be highlighted to the brigade by grouping into one post monthly, e.g. triggered every 1st in month: "Check out new projects started last month Project1, Project2, Project3!"

Do same with meetups.

Some of it could also be added to the update newsletter, feature tracked under #43