Fix typos in layout docs

closes #141

Author: lvivier

docs/layout/grid/index.html

@@ -118,8 +118,8 @@
         <h3 class="f6 ttu tracked mt0">Grids</h3>
         <div>
           <p class="measure f5 f4-ns  lh-copy">
-            You can combine display, float, padding, and widths to contstruct a
-            wide variedy of grids.  Here is a basic example of some options for
+            You can combine display, float, padding, and widths to construct a
+            wide variety of grids.  Here is a basic example of some options for
             constructing a simple grid.
           </p>
         </div>