[MFM] Improve hashtag parsing

src/mfm/language.ts

@@ -142,7 +142,7 @@ export const mfmLanguage = P.createLanguage({
 	},
 	hashtag: () => P((input, i) => {
 		const text = input.substr(i);
-		const match = text.match(/^#([^\s\.,!\?'"#:\/]+)/i);
+		const match = text.match(/^#([^\s\.,!\?'"#:\/\[\]]+)/i);
 		if (!match) return P.makeFailure(i, 'not a hashtag');
 		let hashtag = match[1];
 		hashtag = removeOrphanedBrackets(hashtag);