Update display-3.vim

https://www.w3.org/TR/2021/CRD-css-display-3-20210903/

Author: hail2u

after/syntax/css/display-3.vim

@@ -1,2 +1,3 @@
 syn keyword cssFontAttr contained contents discard
-syn match cssBoxAttr contained "\<ruby\(-\(base\(-group\)\=\|text\(-group\)\=\)\)\=\>"
+syn match cssBoxAttr contained "\<run-in\>"
+syn match cssBoxAttr contained "\<ruby\(-\(base\|text\)\)\=\>"

test/test.css

@@ -245,11 +245,10 @@
 
 .display-3 {
 	display: contents;
+	display: run-in;
 	display: ruby;
 	display: ruby-base;
 	display: ruby-text;
-	display: ruby-base-group;
-	display: ruby-text-group;
 }
 
 .easing-1 {