We should support autolinking matrix aliases, Ids and usernames in the editor

[MTRNord]

Relevant lines:

cetirizine/src/components/input/chat/plugins/AutoLinkPlugin.tsx

Lines 7 to 30 in a97d521

	const MATCHERS: LinkMatcher[] = [
	(text) => {
	const match = URL_MATCHER.exec(text);
	return (
	match && {
	index: match.index,
	length: match[0].length,
	text: match[0],
	url: match[0]
	}
	);
	},
	(text) => {
	const match = EMAIL_MATCHER.exec(text);
	return (
	match && {
	index: match.index,
	length: match[0].length,
	text: match[0],
	url: `mailto:${match[0]}`
	}
	);
	}
	];

[MTRNord]

(Clarification: We should autolink to matrix: (mind the missing slashes!) and NOT to matrix.to. We only want matrix.to support on the reading side for support of legacy clients. We will not support sending matrix.to links)