Add basic Helm chart package

[ljubon]

Relates to #789

Description

The goal of this PR is to convert docker-compose.yml to a basic Helm 3 chart

Checklist

• Add CI steps to support Helm 3 migration
• Publish image jupyter/sparkmagic to ghcr.io
• Publish image jupyter/sparkmagic-livy publishing to ghcr.io
• Stay compatible with docker-compose.yml
• Provide how-to steps

# Create local k8s cluster inside container
kind create cluster --name jupiter

# Install helm chart to container
helm install sparkmagic ./helm
OR
helm upgrade --install sparkmagic ./helm

[devstein]

@ljubon Thank you for doing this! It's a commonly requested feature.

I'll test it out locally later this week. I appreciate the detailed PR description.

[devstein]

Works like a charm locally, thanks for tackling this @ljubon!