Tidy up language around hasFeature().

dom.bs

@@ -4999,14 +4999,13 @@ method, when invoked, must run these steps:
  <li>Return <var>doc</var>.
 </ol>
 
-The <dfn method for="DOMImplementation">hasFeature()</dfn> method
-must return true.
-
-<p class=note>{{hasFeature()}}
-originally would report whether the user agent claimed to support a given DOM
-feature, but experience proved it was not nearly as reliable or granular as
-simply checking whether the desired objects, attributes, or methods existed.
-As such, it should no longer be used, but continues to exist (and simply
+The <dfn method for="DOMImplementation"><code>hasFeature()</code></dfn> method, when
+invoked, must return true.
+
+<p class="note no-backref">{{hasFeature()}} originally would report whether the user agent
+claimed to support a given DOM feature, but experience proved it was not nearly as
+reliable or granular as simply checking whether the desired objects, attributes, or
+methods existed. As such, it is no longer to be used, but continues to exist (and simply
 returns true) so that old pages don't stop working.
 
 </div>

dom.html

@@ -6583,15 +6583,14 @@ <h4 class="heading settled" data-level="4.5.1" id="interface-domimplementation">
 </ol>
 
 
-    <p>The <dfn class="idl-code" data-dfn-for="DOMImplementation" data-dfn-type="method" data-export="" id="dom-domimplementation-hasfeature">hasFeature()<a class="self-link" href="#dom-domimplementation-hasfeature"></a></dfn> method
-must return true.</p>
+    <p>The <dfn class="idl-code" data-dfn-for="DOMImplementation" data-dfn-type="method" data-export="" id="dom-domimplementation-hasfeature"><code>hasFeature()</code><a class="self-link" href="#dom-domimplementation-hasfeature"></a></dfn> method, when
+invoked, must return true.</p>
 
 
-    <p class="note" role="note"><code class="idl"><a data-link-type="idl" href="#dom-domimplementation-hasfeature">hasFeature()</a></code>
-originally would report whether the user agent claimed to support a given DOM
-feature, but experience proved it was not nearly as reliable or granular as
-simply checking whether the desired objects, attributes, or methods existed.
-As such, it should no longer be used, but continues to exist (and simply
+    <p class="note no-backref" role="note"><code class="idl"><a data-link-type="idl" href="#dom-domimplementation-hasfeature">hasFeature()</a></code> originally would report whether the user agent
+claimed to support a given DOM feature, but experience proved it was not nearly as
+reliable or granular as simply checking whether the desired objects, attributes, or
+methods existed. As such, it is no longer to be used, but continues to exist (and simply
 returns true) so that old pages don’t stop working.
 
 </p></div>