feat: Adding docker image support with docker publish Github_action

[bishal7679]

Fixes ⇾ part of #7

Previous State

• Docker building image was missing and also auto publish Docker image through GitHub_action

Current Behavior

• Added Dockerfile to build the harbor-cli image
• Integrated GitHub Action to auto publish the current version of harbor image to Docker hub

Needs to be set

• Set the secrets in the repository scope using below naming convention
  • DOCKER_USERNAME
  • DOCKER_PASSWORD
• Create a separate repository in Docker Hub repository named harbor-cli and Docker hub account name goharbor (can be changed if already existing any account)
  • like this → goharbor/harbor-cli

To trigger the github action, just need to push any changes in main branch or any pull request

//cc @Vad1mo @amands98

[Vad1mo]

Can you build the image an push it to the registry registry.goharbor.io

Image name using thirs domain and library repository name registry.goharbor.io/library/harbor-cli:1.2.3

The creads are in those variables.

• REGISTRY_GOHARBOR_ROBOT_USER_NAME
• REGISTRY_GOHARBOR_ROBOT_USER_SECRET

[bupd]

@bishal7679 fix DCO.