docs(demo/nifi-kafka-druid-water-level-data): Fix Secret Operator link (#130)

Co-authored-by: Techassi <[email protected]>

Author: NickLarsenNZ

docs/modules/demos/pages/nifi-kafka-druid-water-level-data.adoc

@@ -286,7 +286,7 @@ keeps streaming near-real-time updates for every available measuring station.
 You can look at the ingestion job running in NiFi by opening the endpoint `https` from your `stackablectl stacklet list`
 command output. You have to use the endpoint from your command output. In this case, it is https://172.18.0.2:30198.
 Open it with your favourite browser. Suppose you get a warning regarding the self-signed certificate generated by the
-xref:secret-operator::index.adoc[Secret Operator] (e.g. Warning: Potential Security Risk Ahead). In that case, you must
+xref:home:secret-operator:index.adoc[Secret Operator] (e.g. Warning: Potential Security Risk Ahead). In that case, you must
 tell your browser to trust the website and continue.
 
 image::nifi-kafka-druid-water-level-data/nifi_1.png[]