Update images-3.vim

https://www.w3.org/TR/2019/CR-css-images-3-20191010/

Author: hail2u

after/syntax/css/images-3.vim

@@ -1,6 +1,6 @@
 syn match cssFontProp contained "\<object-\(fit\|position\)\>"
 syn match cssFontProp contained "\<image-orientation\>"
-syn keyword cssFontAttr contained snap
+syn keyword cssFontAttr contained snap flip
 syn match cssFontAttr contained "\<scale-down\>"
 syn match cssFontAttr contained "\<from-image\>"
 syn region cssFunction contained matchgroup=cssFunctionName start="\<\(repeating-\(linear\|radial\)-gradient\)\s*(" end=")" oneline keepend

test/test.css

@@ -427,6 +427,7 @@ template {
   object-position: auto;
   image-orientation: auto;
   display: snap;
+  display: flip;
   display: scale-down;
   display: from-image;
   display: repeating-linear-gradient(to bottom, yellow, blue);