Document REST API UUID convention

## Description

There are various reasons why it's advised to use UUIDs instead of IDs when referecing resources through the REST API.

### Resources

- https://www.at7.it/en/blog/rest_uuid_resource
- https://medium.com/@h4t0n/rest-api-uuid-v3-is-the-right-way-3ca0695610dc
-https://towardsdatascience.com/are-uuids-really-unique-57eb80fc2a87

