Add a CONTRIBUTING.md

[ingridcrant]

Initial visual of the CONTRIBUTING.md file

[ingridcrant]

The doc doesn't containing a Getting Started section (I feel that this is covered in the README) or a Testing section (on inspection of the codebase there are no tests for developers to run). If there was anything missed, feel free to suggest changes!

[edif2008]

There are a couple of bits that are missing from these contribution guidelines that would be useful for folks who want to get involved with this project:

• How to test the injector (these can be found in Makefile)

  • Run tests for the operator (as well as any tests that were added)

    make test

  • Run the local version of the injector for functional testing

    # Go to the K8s environment (example for minikube)
    eval $(minikube docker-env)
    
    # Build the local Docker image for the injector
    make build/secrets-injector/local
    
    # Deploy the injector
    make deploy
    
    # Remove the injector from K8s (i.e. cleanup)
    make undeploy

• Debugging - Not sure if this would be possible, but it might be worth investigating.

• Updating documentation - currently manually, in README.

[ingridcrant]

Implemented @edif2008 suggested changes. For reference, this is the new visual of the CONTRIBUTING.md file

[edif2008]

The contribution guidelines look good to me. These should enable folks to set up their environment and add the enhancements they want to the injector.

Approved! ✅