Examples of client registration using different grant

[lo-simon]

Would it be useful to replace register-client-post-request.json with the following 2 examples, one for using client_credentials grant and one for using authorization_code grant?

register-client-credentials-grant-client-post-request.json

{
 "client_name": "My Example Client",
 "grant_types": ["client_credentials"],
 "jwks_uri": "https://client.example.org/my_public_keys.jwks",
 "response_types": ["none"],
 "scope": "registration",
 "token_endpoint_auth_method": "private_key_jwt"
} 

register-authorization-code-grant-client-post-request.json

{
 "client_name": "My Example Client",
 "grant_types": ["authorization_code", "refresh_token"],
 "redirect_uris": [
   "https://client.example.org/callback",
   "https://client.example.org/callback2"
 ],
 "response_types": ["code"],
 "scope": "query connection",
 "token_endpoint_auth_method": "client_secret_basic"
}

[peterbrightwell]

Discussed on call -- this would only mean a change to an example. We agree so @simonlo-sony please do PR

[peterbrightwell]

Closed by #104