add IDs to frequently-referenced parts of the docs

javascript.html

@@ -104,7 +104,7 @@ $('#myModal').on('show.bs.modal', function (e) {
     <h2 id="modals-examples">Examples</h2>
     <p>Modals are streamlined, but flexible, dialog prompts with the minimum required functionality and smart defaults.</p>
 
-    <div class="bs-callout bs-callout-warning">
+    <div class="bs-callout bs-callout-warning" id="callout-stacked-modals">
       <h4>Overlapping modals not supported</h4>
       <p>Be sure not to open a modal while another is still visible. Showing more than one modal at a time requires custom code.</p>
     </div>