`Documentation Fix: Add clear instructions for local dev environment setup`

[Prasad-JB]

Hello! While trying to contribute to the Jupyter Notebook project, I noticed the documentation for setting up a local development environment is a bit sparse and assumes prior experience.

Areas for Improvement:

The configuration for development dependencies (e.g., npm, node, Python 3.x) isn’t clearly defined.

No command example is shown for live-reloading during development (jupyter notebook --NotebookApp.allow_origin='*', etc.).

A troubleshooting section for dependency errors or build failures would help new contributors significantly.

Suggested Enhancements:

Add a brief “Setup for Development” subsection detailing required versions and install commands.

Include usage examples for launching notebook with dev flags.

Provide quick fixes for errors commonly encountered (e.g., missing build tools, failing JS builds).

I’d love to submit a PR if this improvement would be welcome!

[RRosio]

Hi @Prasad-JB, thanks for opening this issue. We talked over this in the triage call, and we would be happy to see a PR for this and discuss the suggested changes in more detail there.

[Prasad-JB]

Thanks, @rrosi
I’ll work on a PR adding the setup instructions, usage examples, and troubleshooting section, and share it soon for review.

[Prasad-JB]

Hi team,

I’ve created and merged the CONTRIBUTING.md guide as requested.

It includes setup instructions, testing and linting commands, contribution guidelines, and the code of conduct for first-time contributors.