[DOCS] Add documentation for mapping to multiple dataset attributes.

[burtenshaw]

The mapping parameter of the Dataset.records.log method accepts multiple target dataset attributes using a list. However, the documentation is limited and only in the API reference.

We should expand documentation with potentially:

• an example in the examples section of the api reference
• an example in the relevant guides.

An example of this is already implemented within unit tests: def test_ingest_record_from_dict_with_mapping_multiple():