extend docs

On-behalf-of: @SAP [email protected]

Author: xrstf

docs/content/publish-resources/templating.md

@@ -27,6 +27,8 @@ for example `join` or `b64enc`. The agent then adds the following functions:
   This function is only available for backwards compatibility when migrating `$variable`-based
   naming rules to use Go templates. New setups should not use this function, but one of the explicitly
   named ones, like `sha256sum` or `sha3sum`.
+* All "objects" mentioned in this documentation refer technically to an `unstructured.Unstructured`
+  value's `.Object` field, i.e. the JSON-decoded representation of a Kubernetes object.
 
 ## Context