Update CSS comments

The margin of lists in IE6/7 is set by 'pt', not relative to the root font-size. This is contrary to the HTML5 spec and other modern browsers, including IE8+.

If people need to customize the list margin, they can either edit normalize.css directly or override later in the source. But at least any non-customised lists will behave consistently now.

normalize.css

@@ -262,6 +262,10 @@ sub {
    Lists
    ========================================================================== */
 
+/*
+ * Addresses margins set differently in IE6/7
+ */
+
 dl,
 menu,
 ol,
@@ -271,16 +275,24 @@ ul {
     margin: 1em 0;
 }
 
+dd {
+    margin: 0 0 0 40px;
+}
+
+/*
+ * Addresses paddings set differently in IE6/7
+ */
+
 details,
 menu,
 ol,
 ul {
     padding: 0 0 0 40px;
 }
 
-dd {
-    margin: 0 0 0 40px;
-}
+/*
+ * Corrects list images handled incorrectly in IE7
+ */
 
 nav ul,
 nav ol {