Add extra features

Signed-off-by: Nikolai Rodionov <allanger@badhouseplants.net>

Author: allanger

docs/database.md

@@ -226,3 +226,21 @@ USER: << base64 encoded user name (generated by db operator) >>
 ```
 
 Then DB Operator will connect to an existing database and set up a user for it.
+
+## Experimantal features
+
+Experimantal features are added via annotations, the following features are available for `Databases`
+
+
+This annotation should be used, when a DbUser is not allowed to log in with password, should be used on the RDS instances, when the SSO is used for authentication.
+
+For more info see this issue: https://github.com/db-operator/db-operator/issues/125
+```yaml
+kinda.rocks/rds-iam-impersonate: "true"
+```
+
+Delete a postgres database with present connectins, might be useful when pgbouncer is used
+
+```yaml
+kinda.rocks/postgres-force-delete-db: "true"
+```