Readme, styling, test

- Update frontend readme to dunk on Chrome and recommend Firefox instead
- Fix some frontend test
- Apply some "styling"

frontend-reactive/app/components/timeline/note.hbs

@@ -1,4 +1,4 @@
-<div>
+<div class="timeline-note">
   <h3>{{@username}}</h3>
   <p>{{@content}}</p>
 </div>

frontend-reactive/app/styles/app.css

@@ -1 +1,6 @@
 /* Ember supports plain CSS out of the box. More info: https://cli.emberjs.com/release/advanced-use/stylesheets/ */
+
+.timeline-note {
+	display: flex;
+	flex-direction: column;
+}