misc: adds contributing file

CONTRIBUTING.md

@@ -0,0 +1,26 @@
+# Contributing
+
+This project is meant to evolve over time be community contributions.
+Feel free to open a Pull Request or an issue to discuss any change or
+enhancement.
+
+## How to contribute.
+
+1. Open an issue on the topic you want to discuss about
+    - Don't forget to add tags, it will be easier to understand the purpose of
+    the issue ;).
+
+2. If you can, fork the repo, make the changes, and create a pull request.
+3. Test if it builds and works. Unit tests may be added later on.
+4. Don't forget documentation !
+
+## Notes
+
+Any change to the code must respect the coding style.
+
+An `.eslintrc.yml` file is provided at the root of the repo to format the
+typescript code.
+
+A `.clang-format` file is provided in the `cppsrc/` folder to format the code.
+
+Any change is welcome !

README.md

@@ -256,9 +256,9 @@ DeviceType.ALL; // device type is both input and output
 -----
 
 ## Contributing
-As an open-source project, every one is free to modify the codebase. Feel free to open any discussion or issue or PR to improve this project.
+See [CONTRIBUTING.md](https://github.com/romlm/native-sound-mixer/blob/master/CONTRIBUTING.md)
 
 -----
 
 ## License
-This project is under [MIT](https://github.com/romlm/native-sound-mixer/blob/develop/LICENSE) license
+This project is under [MIT](https://github.com/romlm/native-sound-mixer/blob/master/LICENSE) license