Add writing modes module to CSS property list

* lisp/textmodes/css-mode.el (css-property-alist): Add new properties
from the CSS Writing Modes Level 3 module.

lisp/textmodes/css-mode.el

@@ -119,7 +119,6 @@
     ("cue" cue-before cue-after)
     ("cue-after" uri "none")
     ("cue-before" uri "none")
-    ("direction" "ltr" "rtl")
     ("display" "inline" "block" "list-item" "inline-block" "table"
      "inline-table" "table-row-group" "table-header-group"
      "table-footer-group" "table-row" "table-column-group"
@@ -180,7 +179,6 @@
     ("stress" number)
     ("table-layout" "auto" "fixed")
     ("top" length percentage "auto")
-    ("unicode-bidi" "normal" "embed" "bidi-override")
     ("vertical-align" "baseline" "sub" "super" "top" "text-top"
      "middle" "bottom" "text-bottom" percentage length)
     ("visibility" "visible" "hidden" "collapse")
@@ -490,6 +488,16 @@
     ;; (https://www.w3.org/TR/css-will-change-1/#property-index)
     ("will-change" "auto" animateable-feature)
 
+    ;; CSS Writing Modes Level 3
+    ;; (https://www.w3.org/TR/css-writing-modes-3/#property-index)
+    ;; "glyph-orientation-vertical" is obsolete and left out.
+    ("direction" "ltr" "rtl")
+    ("text-combine-upright" "none" "all")
+    ("text-orientation" "mixed" "upright" "sideways")
+    ("unicode-bidi" "normal" "embed" "isolate" "bidi-override"
+     "isolate-override" "plaintext")
+    ("writing-mode" "horizontal-tb" "vertical-rl" "vertical-lr")
+
     ;; Filter Effects Module Level 1
     ;; (http://www.w3.org/TR/filter-effects/#property-index)
     ("color-interpolation-filters" "auto" "sRGB" "linearRGB")