Cedar grammar is incorrect

[andrewmwells-amazon]

There are some issues with the Cedar grammar:

• action in Entity should be allowed but isn't
• policy annotations are missing

[bisdavid]

First part of this has been addressed - the Action element has been corrected.

[khieta]

Both resolved in the latest grammar https://docs.cedarpolicy.com/syntax-grammar.html

[bisdavid]

Docs are updated.