[css-images-3] Reorganize image-orientation values to separate the deprecated values from the recommended ones.

Author: tabatkins

css-images-3/Overview.bs

@@ -1386,8 +1386,6 @@ Image Processing {#image-processing}
 	* The height (width) property applies to the vertical (horizontal) dimension of the image,
 		<em>after</em> rotation.
 
-	Values other than ''image-orientation/none'' and ''from-image'' are
-	<em>optional</em> to implement and <em>deprecated</em> in CSS.
 	Values have the following meanings:
 
 	<dl dfn-type=value dfn-for=image-orientation>
@@ -1403,8 +1401,14 @@ Image Processing {#image-processing}
 			this value computes to the angle that the metadata specifies is necessary to correctly orient the image.
 			If necessary, this angle is then rounded and normalized as described above for an <<angle>> value.
 			If there is no orientation specified in its metadata,
-			this value computes to ''0deg''.
+			this value computes to ''image-orientation/none''.
+	</dl>
 
+	Values other than ''image-orientation/none'' and ''from-image'' are
+	<em>optional</em> to implement and <em>deprecated</em> in CSS.
+	They have the following meanings:
+
+	<dl dfn-type=value dfn-for=image-orientation>
 		<dt><dfn><<angle>></dfn>
 		<dd>
 			Positive values cause the image to be rotated to the right