docs: reference kernel_launch README to build custom kernel image

Author: weekenthralling

README.md

@@ -6,7 +6,7 @@ It has been developed using Golang and [Kubebuilder](https://book.kubebuilder.io
 
 ## Spec
 
-First, create configMap from kernel launch file
+First, create configMap from kernel launch file. You can read this [document](./kernel_launch/README.md) to understand the content of the script or build your own image as needed.
 
 ```sh
 kubectl -n <your-namespace> create configmap kernel-launch-scripts --from-file=kernel_launch/bootstrap-kernel.sh --from-file=kernel_launch/launch_ipykernel.py