refactor: migrate parsers to TS (#133)

* dev: finish top-level parsers TS migration

* dev: migrate menu renderers to TS

* chore: fix ts errors

* dev: finish ts migration 🎉

src/parser/classes/RichGrid.ts

@@ -0,0 +1,20 @@
+import Parser from '../index';
+
+import { YTNode } from '../helpers';
+
+class RichGrid extends YTNode {
+  static type = 'RichGrid';
+
+  header;
+  contents;
+
+  constructor(data: any) {
+    super();
+    // XXX: we don't parse the masthead since it is usually an advertisement
+    // XXX: reflowOptions aren't parsed, I think its only used internally for layout
+    this.header = Parser.parse(data.header);
+    this.contents = Parser.parse(data.contents);
+  }
+}
+
+export default RichGrid;