Document reporting configuration

The env vars live in settings.yml, but we need to document how to set up
Mavis for it.

Author: tvararu

README.md

@@ -324,6 +324,10 @@ The `private_key` will automatically be used to generate a JWK on the
 `/oidc/jwks` endpoint, which is used by CIS2 to validate the JWT we use to
 request the access token from CIS2.
 
+### Reporting
+
+See [docs/reporting.md](docs/releasing.md).
+
 #### Key Rotation
 
 Keys should be rotated regularly. When a new key is introduced it's JWK will

docs/reporting.md

@@ -0,0 +1,24 @@
+# Reporting
+
+The reporting service is a separate Python microservice as per
+[ADR 11](../adr/00011-develop-reporting-component-in-python.md).
+
+The codebase is:
+
+https://github.com/NHSDigital/manage-vaccinations-in-schools-reporting
+
+For the reporting functionality, you need to run it in parallel to Mavis.
+
+## Configuration
+
+When developing locally, you can override the default settings in
+`config/settings/development.local.yml`:
+
+```yml
+reporting_api:
+  client_app:
+    token_ttl_seconds: 600
+    root_url: http://localhost:5001 # Or the URL for the reporting app
+    client_id: match_to_.env_in_reporting
+    secret: match_to_.env_in_reporting
+```