Add Helm Chart for LibreTranslate Deployment

[drivard]

This PR introduces a comprehensive Helm chart for the deployment and management of LibreTranslate within a Kubernetes cluster. The chart provides a scalable and flexible solution to handle various deployment scenarios and requirements.

I use the k8s.yaml has the starting boiler plate.

Key Features

• Configurable Parameters: Customize the deployment according to specific needs through values.yaml.
• Persistent Storage Support: Support for both ReadWriteOnce and ReadWriteMany access modes, allowing persistent storage for models and databases.
• Authentication and Security: Integration with basic authentication, security context, and image pull secrets.
• Scalability: Facilitates horizontal scaling with StatefulSets.
• Health Checks: Includes readiness and liveness probes for monitoring the health of the application.
• Documentation: Detailed README with instructions for installation, configuration, and upgrade.

Usage Scenarios

• Deployment on Kubernetes cluster.
• Integration with existing storage solutions like NFS through storage class.
• Support for custom images and private registries.

Testing

The chart has been tested on Kubernetes version 1.26.

• Tested the helm chart using RKE2 Kubernetes cluster on Harvester.
• Tested against the harvester/longhorn default storage class for ReadWriteOnce persistent volume.
• Tested against democratic-csi/nfs on TrueNAS Scale for ReadwriteMany persistent volume.
• Tested scaling of the Statefulset to 1 and 2 replicas with both ReadWriteMany and ReadWriteOnce storage class.

Instructions

The README file includes detailed instructions for installation, customization, and upgrade.

[pierotofy]

Thanks @drivard for this valuable contribution!

[PJ-Finlay]

Awesome thanks @drivard ! Should we add a doc to the main project Readme?

[drivard]

I thought about it let me propose a new pr about it i will look at it at beginning of next week

[drivard]

@PJ-Finlay @pierotofy giving it more thoughts. I am thinking you might want to consider creating a second repository for the chart in order to setup something like describe here in the helm documentation.

I am not having the time now but I will in 2 weeks. I could give it a try if you are interested.

what do you think?