Add plugin documentation for Core and Enterprise

Author: pauldix

content/shared/v3-core-plugins/_index.md

@@ -302,4 +302,4 @@ Trigger specs must be unique across all configured plugins, regardless of which
 
 ```shell
 influxdb3 create trigger --trigger-spec "request:hello-world" --plugin-filename "hellp/hello_world.py" --database mydb hello-world
-```
+```