Merge pull request #45 from orcutt989/patch-11

Update 01-01-letters.html

Author: niccokunzmann

steps/01-01-letters.html

@@ -4,7 +4,7 @@
 lang: en
 ---
 <p>
-  You can search words for letters, determine whether they contain a certain letter.
+  You can search words for letters, and/or determine whether they contain a certain letter.
   Try it yourself. Write the the letter <span class="regex">a</span> into the field below.
 </p>
 <div class="playfield verbose">
@@ -19,5 +19,5 @@
   </ul>
 </div>
 <p>
-  if you do it right, a checkmark appears next to your regular expression.
+  If you do it right, a checkmark appears next to your regular expression.
 </p>