Merge pull request #47 from CodeHeeler/patch-3

Three possible letters for the hint

Author: niccokunzmann

steps/01-02-letters.html

@@ -19,5 +19,5 @@
   </ul>
 </div>
 <p class="hint">
-  It is the letter <span class="regex">u</span> or <span class="regex">r</span>.
+  It is the letter <span class="regex">i</span>, <span class="regex">u</span>, or <span class="regex">r</span>.
 </p>