docs: simplify and clarify installation instructions

[duyaan]

Problem

The current installation instructions in the documentation rely solely on npm install react-admin, which can cause issues or confusion, especially for beginners. Several users (including students) reported difficulties setting up the project this way. The current method is also missing a quick-start guide for local development.

Solution

This PR updates the documentation (README.md) and adds a CONTRIBUTING.md file with a simplified installation workflow:

git clone yarn install cd react-admin yarn run-simple This method is easier to follow, faster to execute, and resolves issues some users encountered with npm-based installs.

How To Test

Clone the repo using the new instructions. Run yarn install, then cd react-admin and yarn run-simple. Confirm the app starts successfully and mirrors expected behavior.

Additional Checks

• [X] The PR targets master for a bugfix or a documentation fix, or next for a feature
• [ ] The PR includes unit tests (if not possible, describe why)
• [ ] The PR includes one or several stories (if not possible, describe why)
• [X] The documentation is up to date

Also, please make sure to read the contributing guidelines.

Closes #10673

[duyaan]

Hi @fzaninotto 👋

Thanks again for the feedback!

I’ve updated the CONTRIBUTING.md file based on your comments. I also wanted to explain the intention behind the changes a bit more clearly:

I’ve been collecting feedback and documentation-related issues — especially those raised by newcomers and students — and noticed recurring problems mentioned in issues like #10662 and #10634. These issues highlight areas where users are encountering setup errors or confusion, particularly during local development and installation.

Since some of these issues (e.g., errors in the current setup video) might take time to resolve or recreate, I thought adding a quick and updated section to the documentation would be helpful in the meantime. The goal is to make the onboarding process smoother for contributors and new users alike, without interfering with the core user installation instructions.

[fzaninotto]

I understand your concern but the solution you propose doesn't work for us:

1. You're using generic content in Contributing
2. You're including a super specific gotcha in contributing that has nothing to do with first time contributors
3. You're degrading the README for non-contributors.

[fzaninotto]

No news for some time, closing.