Add CONTRIBUTING.md to guide new contributors

[samikshakhadka]

This project would benefit from a CONTRIBUTING.md file to help new contributors understand how to participate effectively. Currently, the README covers setup, but contribution guidelines (how to report issues, submit PRs, coding standards, and team coordination) are missing. A dedicated file would streamline onboarding and reduce maintainer workload.

I’d be happy to help draft one if the maintainers agree—let me know your thoughts!

[Mariatta]

The contributing guide now lives in https://pyladiescon-portal-docs.netlify.app/developer/contributing/

Yes we'd like help in adding more content on how to contribute. the codebase is in the same repo here under the /docs folder. We're open to suggestions and contributions.