jQuery.cssNumber: Add a deprecation note

Author: mgol

entries/jQuery.cssNumber.xml

@@ -6,6 +6,9 @@
   </signature>
   <desc>An object containing all CSS properties that may be used without a unit. Prior to jQuery 4.0, the <a href="/css/"><code>.css()</code></a> method uses this object to see if it may append <code>px</code> to unitless values.</desc>
   <longdesc>
+    <div class="warning">
+      <p>Note: This API has been removed in jQuery 4.0; please pass a string value with the desired units instead.</p>
+    </div>
     <p>You can think about <code>jQuery.cssNumber</code> as a list of all CSS properties you might use without a unit. Prior to jQuery 4.0, it was used by <a href="/css/"><code>.css()</code></a> to determine if it needs to add <code>px</code> to unitless values.</p>
     <p>The keys of the <code>jQuery.cssNumber</code> object are camel-cased and the values are all set to <code>true</code>. If you want to prevent the <a href="/css/"><code>.css()</code></a> method from automatically adding the <code>px</code> unit for a specific CSS property and that property is not yet a key of the <code>jQuery.cssNumber</code> object, you can add such an extra property:</p>
     <pre><code>