Update progress-bar.md

Fix valuenow on 25% example

docs/pages/progress-bar.md

@@ -87,7 +87,7 @@ You can add text inside the meter of a progress bar. Make sure the text you use
 </div>
 
 ```html_example
-<div class="progress" role="progressbar" tabindex="0" aria-valuenow="20" aria-valuemin="0" aria-valuetext="25 percent" aria-valuemax="100">
+<div class="progress" role="progressbar" tabindex="0" aria-valuenow="25" aria-valuemin="0" aria-valuetext="25 percent" aria-valuemax="100">
   <span class="progress-meter" style="width: 25%">
     <p class="progress-meter-text">25%</p>
   </span>