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/punctuate.js

@@ -1,13 +1,28 @@
+/**
+ * The `punctuate` helper formats a list of strings (e.g. names) to read
+ * fluently in the application's locale.
+ *
+ * @example
+ * punctuate(['Toby', 'Franz', 'Dominion'])
+ * // Toby, Franz, and Dominion
+ *
+ * @param {Array} items
+ * @return {Array}
+ */
 export default function punctuate(items) {
-  var newItems = [];
+  const punctuated = [];
 
+  // FIXME: update to use translation
   items.forEach((item, i) => {
-    newItems.push(item);
+    punctuated.push(item);
 
-    if (i <= items.length - 2) {
-      newItems.push((items.length > 2 ? ', ' : '')+(i === items.length - 2 ? ' and ' : ''));
+    // If this item is not the last one, then we will follow it with some
+    // punctuation. If the list is more than 2 items long, we'll add a comma.
+    // And if this is the second-to-last item, we'll add 'and'.
+    if (i < items.length - 1) {
+      punctuated.push((items.length > 2 ? ', ' : '') + (i === items.length - 2 ? ' and ' : ''));
     }
   });
 
-  return newItems;
+  return punctuated;
 };