fix: dashboard kube events has bogus config

some copy-paste bugs from the application source section

Author: starpit

plugins/plugin-client-default/notebooks/dashboard.md

@@ -29,8 +29,7 @@ layout:
 
     ```json
     ---
-    include: .source
-    languageFrom: .language
+    language: shell
     ---
     --8<-- "$LOGDIR/events/kubernetes.txt"
     ```