reverting one of previous changes on zcorpan's request

Author: Daniel Glazman

cssom/Overview.bs

@@ -2641,7 +2641,7 @@ The <dfn method for=CSS>escape(<var>ident</var>)</dfn> method must return the re
 </div>
 
 <div class=example>
- The {{CSS/escape()}} method can also be used for serializing URL fragments, although it escapes characters that don't strictly need to be
+ The {{CSS/escape()}} method can also be used for escaping strings, although it escapes characters that don't strictly need to be
  escaped:
  <pre>var element = document.querySelector('a[href="#' + CSS.escape(fragment) + '"]');</pre>
 </div>