Declare conformance to Process Run Crate & validate against it #20

The Federated Learning profile extends Process Run Crate, which is a supported profile in rocrate-validator.

1. add https://w3id.org/ro/wfrun/process/0.5 to conformsTo on the root dataset (can have multiple values so doesn't prevent us conforming to the FL profile as well)
2. validator should check against the profile automatically, but if it doesn't, you can set the profile manually, see the docs https://rocrate-validator.readthedocs.io/en/latest/3_usage_api/
3. resolve any validation issues

Not sure if we do this already, close if we do!