Feature: Description of what an extra does/installs

[TilGP]

As a nvim newbie, it is sometimes hard to understand what the config that an extra changes actually do.
It would be nice to have a short description of the plugins the extra will install.

[jwiede]

Both Extras and Plugins sections need this, if only to help users during initial configuration determine whether specific extras and plugins might be needed by them or not. Since this has been here for over a year without even a reply, though, seems unlikely to happen unless someone external does the work. I'm fine with giving it a shot, so long as there's some decent chance the changes will be accepted.