[css-writing-modes] direction etc. not animatable

w3c#2751 (comment)
direction/writing-mode/unicode-bidi are not animatable

css-writing-modes-3/Overview.bs

@@ -224,7 +224,7 @@ Specifying Directionality: the 'direction' property</h3>
   Inherited: yes
   Percentages: n/a
   Computed value: specified value
-  Animatable: no
+  Animation type: not animatable
   Canonical order: n/a
   </pre>
 
@@ -275,6 +275,7 @@ Embeddings and Overrides: the 'unicode-bidi' property</h3>
   Inherited: no
   Percentages: n/a
   Computed value: specified value
+  Animation type: not animatable
   </pre>
 
   <p class="advisement">Because HTML UAs can turn off CSS styling,
@@ -786,7 +787,7 @@ Block Flow Direction: the 'writing-mode' property</h3>
   Inherited: yes
   Percentages: n/a
   Computed value: specified value
-  Animatable: no
+  Animation type: not animatable
   Canonical order: n/a
   </pre>