Update configuration.md for new wal2json plugin settings (#803)

Author: kvch

docs/configuration.md

@@ -48,6 +48,8 @@ source:
       replication_slot: "pgstream_mydatabase_slot"
       plugin:
         include_xids: false # whether to include transaction IDs in the replication stream events. Defaults to false.
+        add_tables: "public.*" # comma-separated list of tables to include in the wal2json output. Supports wildcards. Filters at the source decode level. Defaults to all tables.
+        filter_tables: "pipelines.*,private.*" # comma-separated list of tables to exclude from the wal2json output. Supports wildcards. Filters at the source decode level. Defaults to empty.
     retry_policy: # retry policy for postgres connections, one of exponential or constant or disable_retries
       disable_retries: false
       exponential:
@@ -195,6 +197,8 @@ Here's a list of all the environment variables that can be used to configure the
 | PGSTREAM_POSTGRES_LISTENER_URL                          | N/A                          | Yes      | URL of the Postgres database to connect to for replication purposes.                                                                                                                                                                                                                                         |
 | PGSTREAM_POSTGRES_REPLICATION_SLOT_NAME                 | "pgstream_dbname_slot"       | No       | Name of the Postgres replication slot name.                                                                                                                                                                                                                                                                  |
 | PGSTREAM_POSTGRES_REPLICATION_PLUGIN_INCLUDE_XIDS       | False                        | No       | Whether to include XIDs in the replication events.                                                                                                                                                                                                                                                           |
+| PGSTREAM_POSTGRES_REPLICATION_PLUGIN_ADD_TABLES         | ""                           | No       | Comma-separated list of tables to include in the wal2json output. Supports wildcards (e.g. `public.*`). Filters at the source decode level, preventing wal2json from generating JSON for excluded tables.                                                                                                    |
+| PGSTREAM_POSTGRES_REPLICATION_PLUGIN_FILTER_TABLES      | ""                           | No       | Comma-separated list of tables to exclude from the wal2json output. Supports wildcards (e.g. `pipelines.*,private.*`). Filters at the source decode level, preventing wal2json from generating JSON for excluded tables.                                                                                     |
 | PGSTREAM_POSTGRES_SNAPSHOT_MODE                         | "full"                       | No       | Mode in which the snapshot will be run. It can be one of `schema`, `data` or `full` (both schema and data).                                                                                                                                                                                                  |
 | PGSTREAM_POSTGRES_SNAPSHOT_TABLES                       | ""                           | No       | Tables for which there will be an initial snapshot generated. The syntax supports wildcards. Tables without a schema defined will be applied the public schema. Example: for `public.test_table` and all tables in the `test_schema` schema, the value would be the following: `"test_table test_schema.\*"` |
 | PGSTREAM_POSTGRES_SNAPSHOT_EXCLUDED_TABLES              | ""                           | No       | Tables that will be excluded in the snapshot process. The syntax does not support wildcards. Tables without a schema defined will be applied the public schema.                                                                                                                                              |