Changes to Creates a conversation

added the new optional request property subject

the response's body type changed from object to no type for status 200

removed the required property body from the response with the 200 status

removed the required property created_at from the response with the 200 status

removed the required property id from the response with the 200 status

removed the required property message_type from the response with the 200 status

removed the required property type from the response with the 200 status

removed the optional property conversation_id from the response with the 200 status

removed the optional property subject from the response with the 200 status

added message to the response body allOf list for the response status 200

added the new optional request property attachment_urls