give all docs callouts IDs

[skip sauce]

docs/_includes/components/progress-bars.html

@@ -3,7 +3,7 @@
 
   <p class="lead">Provide up-to-date feedback on the progress of a workflow or action with simple yet flexible progress bars.</p>
 
-  <div class="bs-callout bs-callout-danger">
+  <div class="bs-callout bs-callout-danger" id="callout-progress-animation-css3">
     <h4>Cross-browser compatibility</h4>
     <p>Progress bars use CSS3 transitions and animations to achieve some of their effects. These features are not supported in Internet Explorer 9 and below or older versions of Firefox. Opera 12 does not support animations.</p>
   </div>