[css-nesting-1] adds CSSNestingRule interface

Author: argyleink

css-nesting-1/Overview.bs

@@ -28,6 +28,16 @@ Module Interactions</h3>
 	This module introduces new parser rules that extend the [[!CSS21]] parser model.
 	This module introduces selectors that extend the [[SELECTORS4]] module.
 
+<pre class=idl>
+interface CSSNestingRule : CSSRule {
+  attribute CSSOMString selectorText;
+  [SameObject] readonly attribute CSSRuleList cssRules;
+  [SameObject, PutForwards=cssText] readonly attribute CSSStyleDeclaration style;
+  unsigned long insertRule(CSSOMString rule, optional unsigned long index = 0);
+  undefined deleteRule(unsigned long index);
+};
+</pre>
+
 <h3 id="values">
 Values</h3>