[css-font-loading] Add a note to the FontFace constructor saying that it doesn't automatically add anything to the font source.

Author: tabatkins

css-font-loading/Overview.bs

@@ -182,6 +182,10 @@ The Constructor</h3>
 			and set <var>font face's</var> <a for=FontFace>status</a> attribute to "error".
 	</ol>
 
+	Note: Note that constructing a <a idl>FontFace</a> object <strong>does not</strong> automatically add it to the document's <a>font source</a>.
+	If it's desired that the newly-constructed <a idl>FontFace</a> object is usable from CSS/etc,
+	it must be explicitly added to the <a>font source</a>.
+
 <h3 id='font-face-load'>
 The <code>load()</code> method</h3>
 

css-font-loading/Overview.html

@@ -276,6 +276,10 @@ <h3 class="heading settled heading" data-level=2.1 id=font-face-constructor><spa
 			and set <var>font face’s</var> <a data-link-for=FontFace data-link-type=idl href=#dom-fontface-status title=status>status</a> attribute to "error".
 	</ol>
 
+<p class=note>	Note: Note that constructing a <a data-link-type=idl href=#dom-fontface title=fontface>FontFace</a> object <strong>does not</strong> automatically add it to the document’s <a data-link-type=dfn href=#font-source title="font source">font source</a>.
+	If it’s desired that the newly-constructed <a data-link-type=idl href=#dom-fontface title=fontface>FontFace</a> object is usable from CSS/etc,
+	it must be explicitly added to the <a data-link-type=dfn href=#font-source title="font source">font source</a>.
+
 <h3 class="heading settled heading" data-level=2.2 id=font-face-load><span class=secno>2.2 </span><span class=content>
 The <code>load()</code> method</span><a class=self-link href=#font-face-load></a></h3>