Starting Oracle GoldenGate for Big Data 21.12, the Documentation gets a new look with the Source and Target Handlers getting distinct topics under the new Replicate Data section.
Furthermore, the Oracle Help Center page gets a major overhaul and is diversified into the following categories:

GoldenGate for Events and Message Streaming

GoldenGate for Big Data and Lakehouses

GoldenGate for Data Warehouses

GoldenGate for NoSQL
The Quickstarts have been appended with a couple of new items:

And all the User Assistance(UA) Assets are accessible from:  https://docs.oracle.com/en/middleware/goldengate/big-data/21.1/index.html.
The Oracl GoldenGate for Big Data 21.12.0.0.0 patch release comprises the following fixes as well:

1. Wrong date format replicating from DB2
2. MONGO REP: org.bson.codecs.configuration.CodecConfigurationException: The uuidRepresentation has not been specified, so the UUID cannot be encoded
3. The connection string contains options without trailing slash
4. Pick better MongoDB error codes for not-found and duplicate errors
5. Handle upsert mode behavior where it does not report rows affected
6. Change Event Handler configuration back to strict
7. MicroServices Snowflake – unable to restart replicat | java.io.InvalidClassException: oracle.goldengate.datasource.meta.TableMetaData; local class incompatible
8. Redis Hash Delivery – ERROR 2023-080-25 20:06:37.000168 [main] – An exception occuredcreating index.