Hide fork-me banner on small screens

Nobody is going to go forking around mobile anyway.

Author: todb

_layouts/default.html

@@ -47,7 +47,7 @@ <h1 class="site-name">{{ site.name }}</h1>
               </center> </p>
             </div>
           </div>
-            <a href="https://github.com/AustinHackers/austinhackers.github.io"><img decoding="async" loading="lazy" width="149" height="149" src="https://github.blog/wp-content/uploads/2008/12/forkme_right_green_007200.png?resize=149%2C149" class="attachment-full size-full" alt="Fork me on GitHub" data-recalc-dims="1" style="position: absolute; top: 0; right: 0; border: 0;"></a>	
+            <a href="https://github.com/AustinHackers/austinhackers.github.io" class="fork-me-banner"><img decoding="async" loading="lazy" width="149" height="149" src="https://github.blog/wp-content/uploads/2008/12/forkme_right_green_007200.png?resize=149%2C149" class="attachment-full size-full" alt="Fork me on GitHub" data-recalc-dims="1" style="position: absolute; top: 0; right: 0; border: 0;"></a>	
         </div>
         {% include text-expand.html %}
     </body>

css/main.css

@@ -292,3 +292,8 @@ table tr:nth-child(even) {
   background-color: #f9f9f9;
 }
 
+@media screen and (max-width: 825px) {
+  .fork-me-banner {
+    display: none;
+  }
+}