Update GCSE CS blog

Insert blog pages via jQuery .load();
Ensure presentation buttons don't have content between them;
Improve styling

page-inserts/navbar.html

@@ -15,5 +15,9 @@
             <i class="material-icons mdc-list-item__graphic" aria-hidden="true">credit_card</i>
             <span class="mdc-list-item__text">Luhn Algorithm</span>
         </a>
+        <a class="mdc-list-item" href="/computer-science-blog/">
+            <i class="material-icons mdc-list-item__graphic" aria-hidden="true">code</i>
+            <span class="mdc-list-item__text">GCSE Computer Science Blog</span>
+        </a>
     </div>
 </div>