docs: Convert slack links to CNCF, add link to contributing guide

CONTRIBUTING.md

@@ -0,0 +1,80 @@
+# Contributing to Cadence Java Samples
+
+We'd love your help in making Cadence great. There are a variety of ways to contribute:
+
+## Ways to Contribute
+
+* **Try out Cadence** and share your feedback via [CNCF Slack](https://slack.cncf.io/) or [GitHub Issues](https://github.com/uber/cadence-java-samples/issues)
+* **Fix or report bugs** by opening [GitHub Issues](https://github.com/uber/cadence-java-samples/issues) or submitting a Pull Request
+* **Add new samples** that demonstrate Cadence features or common use cases
+* **Improve documentation** by fixing typos, adding examples, or clarifying instructions
+* **Share your Cadence success stories** with the community
+
+## General Contributing Guide
+
+Please review our shared [Cadence Contributing Guide](https://github.com/cadence-workflow/contributing) for:
+* Code of Conduct
+* Contributor License Agreement (CLA)
+* General contribution guidelines
+* Development workflow
+* Testing requirements
+
+## Development Setup
+
+### Prerequisites
+
+* Java 8 or later
+* Gradle (included via wrapper)
+* Docker and Docker Compose (for running Cadence Server locally)
+
+### Building the Project
+
+```bash
+./gradlew build
+```
+
+### Running Tests
+
+```bash
+./gradlew test
+```
+
+### Code Style
+
+This project uses Google Java Format. The build will automatically format your code, but you can also run:
+
+```bash
+./gradlew googleJavaFormat
+```
+
+## Adding New Samples
+
+When adding new samples:
+
+1. Place your sample code in the appropriate package under `src/main/java/com/uber/cadence/samples/`
+2. Add corresponding unit tests in `src/test/java/com/uber/cadence/samples/`
+3. Update the main [README.md](README.md) with instructions on how to run your sample
+4. If your sample is complex, consider adding a dedicated README.md in the sample's directory
+
+## Submitting Changes
+
+1. Fork the repository
+2. Create a feature branch from `master`
+3. Make your changes following the code style guidelines
+4. Add tests for your changes
+5. Ensure all tests pass: `./gradlew test`
+6. Commit your changes with a descriptive commit message
+7. Push to your fork and submit a Pull Request
+
+## Getting Help
+
+If you have questions or need help:
+
+* Join the `#cadence` channel on [CNCF Slack](https://slack.cncf.io/)
+* Open a [GitHub Issue](https://github.com/uber/cadence-java-samples/issues)
+* Check the [Cadence documentation](https://cadenceworkflow.io/docs/)
+
+## License
+
+By contributing to Cadence Java Samples, you agree that your contributions will be licensed under the [MIT License](LICENSE.txt).
+

README.md

@@ -141,4 +141,9 @@ To run:
     ./gradlew -q execute -PmainClass=com.uber.cadence.samples.common.RegisterDomain
     ./gradlew -q execute -PmainClass=com.uber.cadence.samples.spring.CadenceSamplesApplication
 
-Apache 2.0 License, please see [LICENSE](https://github.com/cadence-workflow/cadence-java-samples/blob/master/LICENSE.txt) for details.
+## Contributing
+
+We'd love your help in making Cadence great. Please see [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to contribute.
+
+Apache 2.0 License, please see [LICENSE](https://github.com/cadence-workflow/cadence-java-samples/blob/master/LICENSE.txt) for details.
+