features: Standardize width of feature blocks with pseudoelements.

Fixes #9195.

templates/zerver/features.html

@@ -245,6 +245,10 @@
             <p>Zulip is open source, so if something important for
             your use case is missing, you can make it happen!</p>
         </div>
+        <!--Hack: These two pseudo elements are here to ensure the flex
+        arrangment uses the proper cell size with 4 elements in 2 rows.-->
+        <div class="feature-block"></div>
+        <div class="feature-block"></div>
     </section>
 </div>
 {% endblock %}