Implement new MFM syntax

src/mfm/html.ts

@@ -11,6 +11,12 @@ const handlers: { [key: string]: (window: any, token: any, mentionedRemoteUsers:
 		document.body.appendChild(b);
 	},
 
+	big({ document }, { big }) {
+		const b = document.createElement('strong');
+		b.textContent = big;
+		document.body.appendChild(b);
+	},
+
 	code({ document }, { code }) {
 		const pre = document.createElement('pre');
 		const inner = document.createElement('code');

src/mfm/parse/elements/big.ts

@@ -0,0 +1,20 @@
+/**
+ * Bold
+ */
+
+export type TextElementBig = {
+	type: 'big'
+	content: string
+	big: string
+};
+
+export default function(text: string) {
+	const match = text.match(/^\*\*\*(.+?)\*\*\*/);
+	if (!match) return null;
+	const big = match[0];
+	return {
+		type: 'big',
+		content: big,
+		big: match[1]
+	} as TextElementBig;
+}

src/mfm/parse/index.ts

@@ -3,6 +3,7 @@
  */
 
 import { TextElementBold } from './elements/bold';
+import { TextElementBig } from './elements/big';
 import { TextElementCode } from './elements/code';
 import { TextElementEmoji } from './elements/emoji';
 import { TextElementHashtag } from './elements/hashtag';
@@ -15,6 +16,7 @@ import { TextElementTitle } from './elements/title';
 import { TextElementUrl } from './elements/url';
 
 const elements = [
+	require('./elements/big'),
 	require('./elements/bold'),
 	require('./elements/title'),
 	require('./elements/url'),
@@ -30,6 +32,7 @@ const elements = [
 
 export type TextElement = { type: 'text', content: string }
 	| TextElementBold
+	| TextElementBig
 	| TextElementCode
 	| TextElementEmoji
 	| TextElementHashtag