Clarify read-write access via URLs differing from the canonical/read/edit URL

Section Current Text New Text 11.2.2 Requesting Individual Entities   To retrieve an individual entity, the client makes a GET request to the read URL of an entity. To retrieve an individual entity, the client makes a GET request to a URL that identifies the entity, e.g. its read URL. 11.4.3 Update an Entity  (no statement) To update an individual entity, the client makes a PATCH or PUT request to a URL that identifies the entity. Services MAY restrict updates only to requests addressing the edit URL of the entity. 11.4.4 Upsert an Entity An upsert occurs when the client sends an update request to a valid URL that identifies a single entity that does not exist. An upsert occurs when the client sends an update request to a valid URL that identifies a single entity that does not yet exist. 11.4.5 Delete an Entity A successful DELETE request to an entity's edit URL deletes the entity. To delete an individual entity, the client makes a DELETE request to a URL that identifies the entity. Services MAY restrict deletes only to requests addressing the edit URL of the entity.