Update generic.sass link

docs/documentation/overview/classes.html

@@ -26,7 +26,7 @@ doc-subtab: classes
       </p>
       <ul>
         <li>
-          <a href="https://github.com/jgthms/bulma/blob/master/bulma/base/generic.sass"><code>generic.sass</code></a> to define a basic style for your page
+          <a href="https://github.com/jgthms/bulma/blob/master/sass/base/generic.sass"><code>generic.sass</code></a> to define a basic style for your page
         </li>
         <li>
           the <a href="{{ site.url }}/documentation/elements/content/"><code>.content</code> class </a> to use for <em>any</em> textual content, like WYSIWYG