Add warning

Signed-off-by: Faisal Memon <fymemon@yahoo.com>

charts/spire/templates/NOTES.txt

@@ -3,6 +3,10 @@ Installed {{ .Chart.Name }}…
 {{- $s := add (len $up.keyManager) (len $up.nodeAttestor) (len $up.upstreamAuthority) (len $up.notifier) }}
 {{- if gt $s 0 }}
 
-Warning:
-  You are using an unsupported plugin. Functionality of this release and future upgrades are not guaranteed to work smoothly.
+Warning: You're using an unsupported plugin. Functionality of this release and future upgrades aren't guaranteed to work smoothly.
+{{- end }}
+
+{{- if eq ((index .Values "spire-server").experimental.enabled | toString) "true" }}
+
+Warning: You're using an experimental config. Functionality of this release and future upgrades aren't guaranteed to work smoothly.
 {{- end }}