Add missing value

Author: hail2u

after/syntax/css/css-align-3.vim

@@ -1,4 +1,4 @@
 syn match cssFontProp contained "\<\(justify\|align\)-\(self\|content\|items\)\>"
-syn keyword cssFontAttr contained safe unsafe
+syn keyword cssFontAttr contained safe unsafe legacy
 syn match cssFontAttr contained "\<\(self\|flex\)-\(start\|end\)\>"
 syn match cssFontAttr contained "\<space-\(between\|around\|evenly\)\>"

test/test.css

@@ -8,6 +8,7 @@
   display: space-around;
   display: space-between;
   display: space-evenly;
+  display: legacy;
 }
 
 .animations {

test/test.html

@@ -18,6 +18,7 @@
   display: space-around;
   display: space-between;
   display: space-evenly;
+  display: legacy;
 }
 </style>
 <style>