Exclude trailing punctuation from linkified URLs in the timeline #95

A sent message containing https://github.com/githubnext/ace2/issues/91: attach images… renders a link to https://github.com/githubnext/ace2/issues/91:, including the colon. Following the link opens the wrong URL.

Cause

The timeline parses message text with comark (packages/ui/src/components/blocks/parse.ts), whose autolinking keeps a trailing colon:

"Implement https://github.com/githubnext/ace2/issues/91: attach"
-> ["a",{"href":"https://github.com/githubnext/ace2/issues/91:"},"https://github.com/githubnext/ace2/issues/91:"]

Expected

Trailing sentence punctuation (:, ., ,, ;, !, ?, and unbalanced closing brackets) after a bare URL stays outside the link, as in GitHub and other chat apps.

Observed while dogfooding #91 in Ace Canary 0.0.11. Part of #5.