org: bare URL swallows trailing punctuation #209

In krz/skunky-art's README.org, (https://git.macaw.me/skunky/SkunkyArt). renders as a link whose href and text end in )..

go-org's parseAutoLink consumes every RFC 3986 character, and that set includes ., , and ). It never trims trailing punctuation. Upstream v1.9.1, the latest, behaves the same. Org's own plain-link rule stops before trailing punctuation and keeps a ) only when a ( inside the link opened it.