Add contributing guidelines

CONTRIBUTING.md

@@ -0,0 +1,21 @@
+Contributing
+------------
+
+To get started, <a href="https://www.clahub.com/agreements/platformio/platformio">sign the Contributor License Agreement</a>.
+
+1. Fork the repository on GitHub.
+2. Make a branch off of ``develop``
+3. Run ``pip install tox``
+4. Go to the root of project where is located ``tox.ini`` and run ``tox -e develop``
+5. Activate current development environment:
+
+   * Windows: ``.tox\develop\Scripts\activate``
+   * Bash/ZSH: ``source .tox/develop/bin/activate``
+   * Fish: ``source .tox/bin/activate.fish``
+
+6. Make changes to code, documentation, etc.
+7. Lint source code ``tox -e lint``
+8. Run the tests ``tox -e py27``
+9. Build documentation ``tox -e docs`` (creates a directory _build under docs where you can find the html)
+10. Commit changes to your forked repository
+11. Submit a Pull Request on GitHub.

README.rst

@@ -185,22 +185,7 @@ For further details, please refer to `What is PlatformIO? <http://docs.platformi
 Contributing
 ------------
 
-1. Fork the repository on GitHub.
+See `contributing guidelines <https://github.com/platformio/platformio/blob/develop/CONTRIBUTING.md>`_.
-2. Make a branch off of ``develop``
-3. Run ``pip install tox``
-4. Go to the root of project where is located ``tox.ini`` and run ``tox -e develop``
-5. Activate current development environment:
-
-   * Windows: ``.tox\develop\Scripts\activate``
-   * Bash/ZSH: ``source .tox/develop/bin/activate``
-   * Fish: ``source .tox/bin/activate.fish``
-
-6. Make changes to code, documentation, etc.
-7. Lint source code ``tox -e lint``
-8. Run the tests ``tox -e py27``
-9. Build documentation ``tox -e docs`` (creates a directory _build under docs where you can find the html)
-10. Commit changes to your forked repository
-11. Submit a Pull Request on GitHub.
 
 Licence
 -------