[Feature Request] Support self reference using definitions

[gilles-yvetot]

Amazing job on this plugin @DScheglov
I have a schema that reference itself. Kind like a tree. Your plugin add a $ref that point to an $id but ajv does not understand.

Do you think adding a definition would be possible? If yes, and you need help, maybe you could point me in the right direction to help you out.

[gilles-yvetot]

So the actual issue was that the key id needed to be $id so after converting the schema I am replacing id with $id