Add note about supervisor preset stage

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

Author: douglascamata

charts/opentelemetry-collector/values.yaml

@@ -359,6 +359,9 @@ presets:
   # Configures the collector to communicate with the remote Coralogix fleet management service.
   fleetManagement:
     enabled: false
+    # IMPORTANT: The `supervisor` preset is in alpha stage and under heavy development.
+    # It's not recommended for use in production environments.
+    # Support will be provided only when it reaches a stable release.
     supervisor:
       enabled: false
     agentType: ""