[css-align] Correct applies to error for justify-items (doesn't apply to flex containers)

Author: fantasai

css-align/Overview.bs

@@ -868,7 +868,7 @@ Inline/Main-Axis Alignment: the 'justify-items' property</h3>
 	Name: justify-items
 	Value: auto | stretch | <<baseline-position>> | [ <<self-position>> && <<overflow-position>>? ] | [ legacy && [ ''<content-position>/left'' | ''<content-position>/right'' | ''<content-position>/center'' ] ]
 	Initial: auto
-	Applies to: block containers, flex containers, and grid containers
+	Applies to: block containers and grid containers
 	Inherited: no
 	Percentages: n/a
 	Media: visual