If you wish to include the schema for a YAML file in an existing model, with your model already opened, choose Tools > Reverse-Engineer > JSON document.
The process includes detection of ISO 8601 date/time/timestamp/duration in strings when target supports such data types.
The structure of a YAML file can be imported either as an entity in the Entity Relationship Diagram, or alternatively as a model definition so it could be re-used in the model:
If you wish to force the destination of the reverse-engineering operation, you may specify the container in which the entities should be inserted.
For RDBMS targets, an additional option appears, that allows automatic normalization of complex data types: