[css-backgrounds-4] Added repeat-block and repeat-inline keywords for background-repeat (#10755)

Author: SebastianZ

css-backgrounds-4/Overview.bs

@@ -463,7 +463,7 @@ Tiling Images Shorthand: the 'background-repeat' property</h3>
 	'background-repeat-x' and 'background-repeat-y' longhand properties.
 
 	<pre class=prod>
-		<dfn><<repeat-style>></dfn> = repeat-x | repeat-y | <<repetition>>{1,2}
+		<dfn><<repeat-style>></dfn> = repeat-x | repeat-y | repeat-block | repeat-inline | <<repetition>>{1,2}
 	</pre>
 
 	<p>Single values for <<repeat-style>> have the following
@@ -478,6 +478,14 @@ Tiling Images Shorthand: the 'background-repeat' property</h3>
 	<dd>
 	Computes to ''no-repeat repeat''.
 
+	<dt><dfn>repeat-block</dfn>
+	<dd>
+	Computes to ''repeat'' in the [=block axis=] and ''no-repeat'' in the [=inline axis=].
+
+	<dt><dfn>repeat-inline</dfn>
+	<dd>
+	Computes to ''repeat'' in the [=inline axis=] and ''no-repeat'' in the [=block axis=].
+
 	<dt>''background-repeat-x/repeat''
 	<dd>
 	Computes to ''repeat repeat''.
@@ -2027,6 +2035,7 @@ Additions since [[CSS3BG]]</h3>
 	* added ''background-clip/border-area'' and ''background-clip/text'' values to 'background-clip'
 	* added 'background-tbd'
 	* added 'background-repeat-*' longhands
+	* added logical keywords ''background-repeat/repeat-block'' and ''background-repeat/repeat-inline'' to 'background-repeat'
 
 <h2 id="acknowledgments">
 Acknowledgments</h2>