[css-fonts-4] add Graphite local reference

Author: svgeesus

css-fonts-4/Overview.bs

@@ -29,6 +29,17 @@ spec:fetch; type:dfn; for:/; text:request
 spec:fetch; type:dfn; for:/; text:fetch
 </pre>
 
+<pre class=biblio>
+	{
+		"GRAPHITE": {
+			"href": "https://scripts.sil.org/cms/scripts/page.php?site_id=projects&item_id=graphite_techAbout",
+			"title": "Graphite technical overview",
+			"publisher": "SIL",
+			"date": "2012"
+		}
+	}
+</pre>
+
 
 <h2 id="introduction">
 Introduction</h2>
@@ -2172,7 +2183,9 @@ The <dfn id="at-font-face-rule">''@font-face''</dfn> rule</h3>
 
     The 'features' requirement refers to support for font features,
     commonly implemented in [[!OPENTYPE]] with the <code>GSUB</code> and the <code>GPOS</code> tables,
-    as well as in [[!AAT-FEATURES]] using the <code>morx</code> table.
+    as well as in [[!AAT-FEATURES]] using the <code>morx</code> and <code>kerx</code> tables
+	and [[!GRAPHITE]] with the <code>Silf</code>, <code>Glat </code>, <code>Gloc </code>,
+	<code>Feat </code> and <code>Sill </code> tables.
     The section on [[#font-rend-props]] describes properties that interact with these facilities.
 
     The 'variations' requirement refers to the support of font variations,