Adds CSS transitions feature

[vwallen]

No description provided.

[autonome]

James is better for review of feature composition here, but early feedback on the group is that should remove -css and instead make this a child of the css group, see example: https://github.com/web-platform-dx/web-features/blob/main/groups/transforms.yml

[jamesnw]

James is better for review of feature composition here, but early feedback on the group is that should remove -css and instead make this a child of the css group, see example: https://github.com/web-platform-dx/web-features/blob/main/groups/transforms.yml

I agree on making this a child of the css group.

I think we can remove -css from the filename/id, but keep the (CSS) in the name. There's more discussion on #1771 (comment) about distinguishing the methods of making things move.

[ddbeck]

I think this is ready to land with a rename from transitions-css.yml to transitions.yml (and the refresh based on that)

[jamesnw]

🚀

Requested changes have been incorporated