Fix typos

Author: mrego

index.html

@@ -152,7 +152,7 @@ <h4 class="list-group-item-heading">z-index</h4>
                                     <a href="https://github.com/Igalia/css-grid-layout/blob/gh-pages/z-index.png" class="label label-info">screenshot</a>
                                     <a href="http://www.w3.org/TR/css-grid/#z-order" class="label label-warning">spec</a>
                                 </p>
-                                <p>Example with several overlaping grid items where painting order is defined by the implicit DOM order and different z-index values.</p>
+                                <p>Example with several overlapping grid items where painting order is defined by the implicit DOM order and different z-index values.</p>
                             </li>
                             <li class="list-group-item">
                                 <h4 class="list-group-item-heading">Explicit Grid Shorthand: grid-template</h4>
@@ -275,7 +275,7 @@ <h4 class="list-group-item-heading">Auto-placement Algorithm</h4>
                                     <a href="https://github.com/Igalia/css-grid-layout/blob/gh-pages/autoplacement.png" class="label label-info">screenshot</a>
                                     <a href="http://dev.w3.org/csswg/css-grid/#auto-placement-algo" class="label label-warning">spec</a>
                                 </p>
-                                <p>Auto-placement algorithm demo. Allow to new add grid items in different positions in order to check how the algorithm works. Also, includes the possibitly to change between the different <code>grid-auto-flow</code> property values.</p>
+                                <p>Auto-placement algorithm demo. Allow to new add grid items in different positions in order to check how the algorithm works. Also, includes the possibility to change between the different <code>grid-auto-flow</code> property values.</p>
                             </li>
                         </ul>
                     </div>