feat: support TriggerAuthentication properties from ConfigMap

Signed-off-by: Jan Wozniak <[email protected]>

content/docs/2.13/authentication-providers/configmap.md

@@ -0,0 +1,14 @@
++++
+title = "ConfigMap"
++++
+
+You can pull information into the trigger by defining the `name` of the Kubernetes `ConfigMap` and the `key` to use.
+
+```yaml
+configMapTargetRef:                       # Optional.
+  - parameter: connectionString           # Required - Defined by the scale trigger
+    name: my-keda-configmap-resource-name # Required.
+    key: azure-storage-connectionstring   # Required.
+```
+
+**Assumptions:** `namespace` is in the same resource as referenced by `scaleTargetRef.name` in the `ScaledObject`, unless specified otherwise.