ATEAM-10574 update docs for local testing

[cmckeen]

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

Fixes #99

Proposed Changes

• Added a new Goreleaser yaml that only builds the image locally without attempting to publish to Dockerhub
• Created a separate Drone pipeline that can be when running drone locally

Description

• Did the above, and added relevant entries to the changelog and CONTRIBUTING.MD

Checklist

• Read the CONTRIBUTING document.
• Read the CODE OF CONDUCT document.
• Add tests to cover changes.
• Ensure your code follows the code style of this project.
• Ensure CI and all other PR checks are green OR
  • Code compiles correctly.
  • Created tests which fail without the change (if possible).
  • All new and existing tests passed.
• Add your changes to Unreleased section of CHANGELOG.
• Improve and update the README (if necessary).
• Ensure documentation is up-to-date. The same file will be updated in plugin index when your PR is accepted, so it will be available for end-users at http://plugins.drone.io.