Remove unneeded spaces from `pre`.

docs/_includes/css/code.html

@@ -16,7 +16,7 @@ For example, <code>&lt;section&gt;</code> should be wrapped as inline.
   To switch directories, type <kbd>cd</kbd> followed by the name of the directory.
 </div>
 {% highlight html %}
-  To switch directories, type <kbd>cd</kbd> followed by the name of the directory.
+To switch directories, type <kbd>cd</kbd> followed by the name of the directory.
 {% endhighlight %}
 
   <h2 id="code-block">Basic block</h2>