Add CONTRIBUTING file and pre-commit hook instructions

CONTRIBUTING.md

@@ -0,0 +1,74 @@
+# Contributing to JAXsim :rocket:
+
+Hello Contributor,
+
+We're thrilled that you're considering contributing to JAXsim!
+Here's a brief guide to help you seamlessly become a part of our project.
+
+## Development Environment :hammer_and_wrench:
+
+Make sure your development environment is set up.
+Follow the installation instructions in the [README](./README.md) to get JAXsim and its dependencies up and running.
+
+To ensure consistency and maintain code quality, we recommend using the pre-commit hook with the following configuration.
+This will help catch issues before they become a part of the project.
+
+### Setting Up Pre-commit Hook :fishing_pole_and_fish:
+
+`pre-commit` is a tool that manages pre-commit hooks for your project.
+It will run checks on your code before you commit it, ensuring that it meets the project's standards.
+You should have it already installed if you followed the installation instructions in the [README](./README.md).
+
+Run the following command to install the hooks:
+
+```bash
+pre-commit install
+```
+
+### Using Pre-commit Hook :vertical_traffic_light:
+
+Before making any commits, the pre-commit hook will automatically run.
+If it finds any issues, it will prevent the commit and provide instructions on how to fix them.
+
+To get your commit through without fixing the issues, use the `--no-verify` flag:
+
+```bash
+git commit -m "Your commit message" --no-verify
+```
+
+To manually run the pre-commit hook at any time, use:
+
+```bash
+pre-commit run --all-files
+```
+
+## Making Changes :construction:
+
+Before submitting a pull request, create an issue to discuss your changes if major changes are involved.
+This helps us understand your needs and provide feedback.
+Clearly describe your pull request, referencing any related issues.
+Follow the [PEP 8](https://peps.python.org/pep-0008/) style guide and include relevant tests.
+
+## Testing :test_tube:
+
+Your code will be tested with the CI/CD pipeline before merging.
+Feel free to add new ones or update the existing tests in the [workflows](./github/workflows) folder to cover your changes.
+
+## Documentation :book:
+
+Update the documentation in the [docs](./docs) folder and the [README](./README.md) to reflect your changes, if necessary.
+There is no need to build the documentation locally; it will be automatically built and deployed with your pull request, where a preview link will be provided.
+
+## Code Review :eyes:
+
+Expect feedback during the code review process.
+Address comments and make necessary changes.
+This collaboration ensures quality.
+Please keep the commit history clean, or squash commits if necessary.
+
+## License :scroll:
+
+JAXsim is under the [BSD 3-Clause License](./LICENSE).
+By contributing, you agree to the same license.
+
+Thank you for contributing to JAXsim! Your efforts are appreciated.

README.md

@@ -89,8 +89,8 @@ Here below we summarize the differences between the projects:
 
 ## Contributing
 
-Pull requests are welcome. 
-For major changes, please open an issue first to discuss what you would like to change.
+We welcome contributions from the community.
+Please read the [contributing guide](./CONTRIBUTING.md) to get started.
 
 ## Citing