Massive JavaScript cleanup

- Use JSX for templates
- Docblock/comment everything
- Mostly passes ESLint (still some work to do)
- Lots of renaming, refactoring, etc.

CSS hasn't been updated yet.

js/lib/helpers/fullTime.js

@@ -0,0 +1,15 @@
+/**
+ * The `fullTime` helper displays a formatted time string wrapped in a <time>
+ * tag.
+ *
+ * @param {Date} time
+ * @return {Object}
+ */
+export default function fullTime(time) {
+  const mo = moment(time);
+
+  const datetime = mo.format();
+  const full = mo.format('LLLL');
+
+  return <time pubdate datetime={datetime}>{full}</time>;
+}