Adding 4 new terms in NIP-24 to the Nostr Ontology

I've raised an issue to add 4 new terms to the nostr ontology:

https://github.com/nostrcg/schema/issues/7

The following 4 fields could be added to the schema, and are in wide usage:

   - display_name: an alternative, bigger name with richer characters than
   name. name should always be set regardless of the presence of
   display_name in the metadata.
   - website: a web URL related in any way to the event author.
   - banner: an URL to a wide (~1024x768) picture to be optionally
   displayed in the background of a profile screen.
   - bot: a boolean to clarify that the content is entirely or partially
   the result of automation, such as with chatbots or newsfeeds.

The first being a string, the next 2 URIs, and the final term a boolean

The base protocol terms are already in the ontology, but not yet the
extended profile.  I notice that `name` field is not there either, perhaps
that's also a good one to add.

LMK if there's any feedback on this, happy to improve the schema, either
here on the mailing list, or in the github area.