Add color-adjust-1.vim

See also: https://www.w3.org/TR/2019/WD-css-color-adjust-1-20190521/

after/syntax/css/color-4.vim

@@ -1,3 +1,2 @@
-syn match cssColorProp contained "\<color-adjust\>"
 syn region cssFunction contained matchgroup=cssFunctionName start="\<\(hwb\|lab\|lch\|gray\|color\|device-cmyk\=\)\s*(" end=")" oneline keepend
 syn match cssFontDescriptor "@color-profile\>" nextgroup=cssFontDescriptorBlock skipwhite skipnl

after/syntax/css/color-adjust.vim

@@ -0,0 +1,3 @@
+syn match cssColorProp contained "\<\(forced-\)\=color-adjust\>"
+syn match cssColorProp contained "\<color-scheme\>"
+syn keyword cssFontAttr contained only economy exact