fix buttons links

docs/docs.html

@@ -1909,7 +1909,7 @@ For example, <code>&lt;section&gt;</code> should be wrapped as inline.
             <h1>Buttons</h1>
           </div>
 
-          <h2>Default buttons</h2>
+          <h2 id="buttons-options">Button options</h2>
           <p>Button styles can be applied to anything with the <code>.btn</code> class applied. However, typically you'll want to apply these to only <code>&lt;a&gt;</code> and <code>&lt;button&gt;</code> elements for the best rendering.</p>
           <div class="bs-docs-example">
             <button type="button" class="btn btn-default">Default</button>