Add feature for individual transform properties (web-platform-dx#565)

Author: foolip

feature-group-definitions/individual-transforms.yml

@@ -0,0 +1,11 @@
+name: Individual transform properties
+description: Transform elements with separate `translate`, `rotate`, and `scale` CSS properties.
+spec: https://drafts.csswg.org/css-transforms-2/#individual-transforms
+usage_stats:
+  - https://chromestatus.com/metrics/css/timeline/popularity/504 # translate
+  - https://chromestatus.com/metrics/css/timeline/popularity/505 # rotate
+  - https://chromestatus.com/metrics/css/timeline/popularity/506 # scale
+compat_features:
+  - css.properties.rotate
+  - css.properties.scale
+  - css.properties.translate