[css-conditional-3] More changes updates

Author: svgeesus

css-conditional-3/Overview.bs

@@ -692,6 +692,8 @@ The following (non-editorial) changes were made to this specification since the
   <li>Moved the definition of @supports selector to css-conditional-4.
   <li>''@supports''' is no longer at risk.
   <li>Rewrote to use CSS Syntax grammars, not CSS 2.1 grammars
+  <li>Changed from CSS Interface to WebIDL-compatible CSS namespace
+  <!-- changes before Oct 12, 2017 are not in GitHub. Should be in Mercurial? -->
   <li>Dropped requirement for spaces around ''and'', ''or'', and ''not'' keywords
       for consistency with <a href="http://www.w3.org/TR/css3-mediaqueries/">Media Queries</a>
       (which are themselves constrained by compatibility with the output of some CSS minimizers