openSearch: skrivefeil

fixes #744
Co-authored-by: atroberthtollefsen <[email protected]>

Author: Kyrremann

docs/persistence/opensearch/reference/README.md

@@ -11,7 +11,7 @@ The `spec.opensearch` configuration has two fields as you get exactly one OpenSe
 
 ```yaml
     spec:
-      opensearch:
+      openSearch:
         instance: <OpenSearchInstanceName>
         access: readwrite | read | write | admin
 ```