docs: add CONTRIBUTING.md with development and contribution guidelines

[onkar717]

Summary

Add a CONTRIBUTING.md file to help new contributors understand how to set up the project, run tests, and submit changes.

This guide was prepared after reviewing the repository build system, Makefile targets, and existing documentation.

Related issue

Fixes #232

What is included

This adds a basic contributor guide covering:

• Required development tools
• Local setup and build steps
• How to run unit and e2e tests
• Linting and formatting checks
• General PR workflow

Notes

This is a documentation-only change and does not modify any functionality.
The content was prepared by reviewing the existing README, Makefile targets, and repository structure.

[mmadzin]

It looks like it's AI generated. It contains lots of redundant information from already existing documentation and it also contains multiple mistakes.

Please run the commands from the suggested documentation and make sure it works.

[onkar717]

Thanks for the feedback.

I reviewed the existing project documentation and prepared this guide based on the current README, Makefile targets, and repository structure. I only used AI assistance for minor rephrasing and formatting, but I agree the document should be more concise and strictly project-focused.

I'll rework the CONTRIBUTING.md to remove redundant information and ensure all commands are verified locally. If some parts fit better in the README instead, I can also move them there.

I'll push an updated version shortly.

[onkar717]

@mmadzin such many org have the sperate clear focused the CONTRIBUTING.md and README.md

[onkar717]

I reworked CONTRIBUTING.md to be concise and strictly repository-focused.

I ran the following from this branch:

• make help
• make build
• make lint-config
• make test executes but currently fails in runtime due to an existing panic in internal/controller/webserver_controller_test.go (nil pointer dereference during controller test). This appears to be a current test/runtime issue rather than a docs issue.

@mmadzin