Change "right sidebar" and add graphic' from github's help to ease un…

…derstanding.

Methinks there is not a sidebar anymore for this exercise... Github needs to update the wording in their help guides as well, I'd say.

guide/challenges/forks_and_clones.html

@@ -65,7 +65,7 @@ <h2>Forks</h2>
       <h2>Step: Fork Patchwork Repository</h2>
       <p>The project we'll work with is <a href="http://github.com/jlord/patchwork" target="_blank">github.com/jlord/patchwork</a>. Go to that site and click the fork button at the top right. Once the
         fork animation is complete, you've got a copy on your account. Copy
-        your fork's HTTP URL on the right sidebar.</p>
+        your fork's HTTP URL from the repo's address bar. <br><img src="https://help.github.com/assets/images/help/repository/clone-repo-clone-url-button.png">.</p>
 
       <h2>Step: Clone Fork Locally</h2>
       <p>Now, in terminal, clone the repository onto your computer. It will create a new folder
@@ -151,4 +151,4 @@ <h2>Tips</h2>
 
       </script>
     </body>
-</html>
+</html>