Merge pull request #11718 from KostyaTretyak/once

Added link to Ukrainian translation website (in about.html)

about.html

@@ -88,6 +88,7 @@ base_url: "../"
     <li><a href="http://v3.bootcss.com/">Bootstrap 中文文档 (Chinese)</a></li>
     <li><a href="http://www.oneskyapp.com/docs/bootstrap/ru">Bootstrap по-русски (Russian)</a></li>
     <li><a href="http://www.oneskyapp.com/docs/bootstrap/es">Bootstrap en Español (Spanish)</a></li>
+    <li><a href="http://twbs.site-konstruktor.com.ua">Bootstrap ua Українською (Ukrainian)</a></li>
   </ul>
   <p>Have another language to add, or perhaps a different or better translation? Let us know by <a href="https://github.com/twbs/bootstrap/issues/new">opening an issue</a>.</p>
 </div>