ADR about the use of submissions

[felipemontoya]

During the development of phase one, we decided to use edx-submissions to capture the messages from and to the llm. This decision was not documented nor was any feedback gathered from experts in the use of submissions. So far it has worked, but I still think this could be controversial.

I think we need to capture the decision in an ADR and ask for feedback from some community experts. I'm thinking dave, kyle or feanil from axim could give us some perspective. Jill is listed as a maintainer in the cc page, but not in the catalog-yaml

[felipemontoya]

https://github.com/openedx/openedx-ai-extensions/blob/main/backend/openedx_ai_extensions/processors/openedx/submission_processor.py