[css mode] Add two left-out braces on the demo pages

mode/css/less.html

@@ -146,7 +146,7 @@ fieldset span button, fieldset span input[type="file"] {
       });
     </script>
 
-    <p>The LESS mode is a sub-mode of the <a href="index.html">CSS mode</a> (defined in <code>css.js</code>.</p>
+    <p>The LESS mode is a sub-mode of the <a href="index.html">CSS mode</a> (defined in <code>css.js</code>).</p>
 
     <p><strong>Parsing/Highlighting Tests:</strong> <a href="../../test/index.html#less_*">normal</a>,  <a href="../../test/index.html#verbose,less_*">verbose</a>.</p>
   </article>

mode/css/scss.html

@@ -150,7 +150,7 @@ code {
       });
     </script>
 
-    <p>The SCSS mode is a sub-mode of the <a href="index.html">CSS mode</a> (defined in <code>css.js</code>.</p>
+    <p>The SCSS mode is a sub-mode of the <a href="index.html">CSS mode</a> (defined in <code>css.js</code>).</p>
 
     <p><strong>Parsing/Highlighting Tests:</strong> <a href="../../test/index.html#scss_*">normal</a>,  <a href="../../test/index.html#verbose,scss_*">verbose</a>.</p>