community/notcurses: upgrade to 2.3.0
Upgrade to 2.3.0 from 2.2.11. Very few user-visible changes, pretty much just a version bump on the 2.2.11 "release candidate".
https://github.com/dankamongmen/notcurses/releases/tag/v2.3.0
Also, we now grab the pregenerated documentation package (built with each release), unpack it, and install the man pages into the notcurses-doc
package (https://github.com/dankamongmen/notcurses/issues/1638), so the manual pages are available on Alpine.