Fix typo in index-START.html

Author: Ememme

10 - Hold Shift and Check Checkboxes/index-START.html

@@ -75,7 +75,7 @@
     </div>
     <div class="item">
       <input type="checkbox">
-      <p>Everything inbetween should also be set to checked</p>
+      <p>Everything in between should also be set to checked</p>
     </div>
     <div class="item">
       <input type="checkbox">