add version to docs homepage, fix docs example for forms

docs/base-css.html

@@ -920,7 +920,7 @@ For example, <code>section</code> should be wrapped as inline.
   <label class="checkbox">
     <input type="checkbox"> Remember me
   </label>
-  <button type="submit" class="btn">Go</button>
+  <button type="submit" class="btn">Sign in</button>
 </form>
 </pre>
     </div>