add aep.api.resource annotation for resources #40
Description
Similar to google.api.resource, the aeps should have their own proto annotation for resources (to allow for extensions of new metadata as needed). see https://buf.build/googleapis/googleapis/file/main:google/api/resource.proto.
The annotation should have a limited subset of the original fields (plural, singular, type, and patterns). Also the parents repeated string field should be added, to enable the specification of one or more parents of the resource.