AWS RDS PostgreSQL wal2json replication

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Describe the issue
Missing instructions for RDS PostgreSQL as a data source using wal2json plugin

The relevant Arcion product or service
Arcion Replicant CDC replication

Expected behavior
Instructions to be available specific to AWS RDS PostgreSQL as a source

Actual behavior
N/A

The part of the documentation that requires updating
https://docs.arcion.io/docs/source-setup/postgresql/

These are the steps we will need to follow to set up RDS PostgreSQL using the wal2json plugin
Creating Parameter Group

1. Create a database paraemter group if one is not already being used for the RDS PostgreSQL database
2. In the parameter group, change rds.logical_replication = 1 # This automatically sets wal_level = logical
3. Make sure max_replication_slots is 1 or greater than the number of replication jobs that will need to be ran from this RDS instance
4. Create a user for replication in the source RDS PostgreSQL database
5. Grant permissions:
   5a. GRANT USAGE ON SCHEMA "" TO ;
   GRANT SELECT ON ALL TABLES IN SCHEMA "" TO ;
   ALTER ROLE WITH REPLICATION;
6. Log into the PostgreSQL database/catalog with a privileged account that will be replicated.
7. Create a logical replication slot in this database/catalog
   #Note the wal2json plugin is availabe for RDS PostgreSQL, so no additional software installation is required
   7a. SELECT 'init' FROM pg_create_logical_replication_slot('<replication_slot_name>', 'wal2json');
8. Verify the slot has been created
   8a. SELECT * from pg_replication_slots;

Additional information
Any other details or screenshots that you think might be relevant.