Add batch distributor notification config

docs/config.md

@@ -104,6 +104,17 @@ report rendering succeeds and final metadata is saved.
   ```yaml
   - "{valid_start_date}/{artifact_group}/{valid_start_date}-{artifact_group}-{run_id}.md"
   ```
+- `batch.enabled`: whether batch distributor notification config is active
+  when distributor notification is enabled. Default: `true`.
+- `batch.pipeline_id_template`: template for batch distributor pipeline IDs.
+  Required when distributor notification and batch notification are enabled.
+  Default: `weatherreporter`.
+- `batch.bundle_id_template`: template for batch distributor bundle IDs.
+  Required when distributor notification and batch notification are enabled.
+  Default: `weatherreporter.{location_id}.{batch}`.
+- `batch.idempotency_key_template`: template for batch distributor idempotency
+  keys. Required when distributor notification and batch notification are
+  enabled. Default: `{bundle_id}.{batch_run_id}`.
 
 Supported template variables are `location_id`, `report_id`, `run_id`,
 `artifact_group`, `batch_output_name`, `valid_start_date`, `valid_end_date`,
@@ -116,6 +127,11 @@ The rendered pipeline ID selects the configured distributor `http_upload`
 workflow. The rendered bundle ID is the stable logical source identity for the
 report stream. The rendered idempotency key is the per-run retry identity.
 
+Batch templates support `location_id`, `batch`, `batch_run_id`, and
+`batch_started_date`. Batch idempotency templates may also use `bundle_id`.
+Batch bundle IDs identify a logical batch stream; batch idempotency keys
+identify a specific retryable batch attempt.
+
 Rendered report paths must be unique relative paths with `/` separators. They
 must not contain backslashes, empty path segments, `.`, `..`, `manifest.json`,
 or `.distributor.json`.