feat(notes): Add templating for Notes in oD

Signed-off-by: Axel Lender <lender@b1-systems.de>

docs/external-secrets.md

@@ -13,6 +13,7 @@ This document covers how to utilise external secrets and special requirements.
   * [Cassandra](#cassandra)
   * [Keycloak](#keycloak)
   * [MinIO](#minio)
+  * [Notes](#notes)
   * [XWiki](#xwiki)
 <!-- TOC -->
 
@@ -73,6 +74,20 @@ stringData:
 
 Further we need the credentials introduced at MinIO in various other components that didn't implement the special format from MinIO. Hence we have to create key-value-pairs of the passwords for them.
 
+## Notes
+
+There are some values that consist of more than just one secret part.
+
+```yaml
+backend:
+  configuration:
+    django:
+      superuserEmail:
+        value: {{ printf "default.admin@%s" .Values.global.domain | quote }}
+    redisUrl:
+      value: "redis://default:{{ .Values.cache.notes.password | default .Values.secrets.redis.password }}@{{ .Values.cache.notes.host }}:{{ .Values.cache.notes.port }}/7"
+```
+
 ## XWiki
 
 Properties listed in the file of the external secret will overwrite plain values.