--- /dev/null
+Contributing
+============
+
+First of all, **thank you** for contributing, **you are awesome**! :)
+
+If you have an idea or found a bug, please [open an issue](https://github.com/cebe/markdown/issues/new) on github.
+
+If you want to contribute code, there a few rules to follow:
+
+- I am following a code style that is basically [PSR-2](http://www.php-fig.org/psr/2/) but with TABS indentation (yes, I really do that ;) ).
+ I am not going to nit-pick on all the details about the code style but indentation is a must. The important part is that code is readable.
+ Methods should be documented using phpdoc style.
+
+- All code must be covered by tests so if you fix a bug or add a feature, please include a test case for it. See below on how that works.
+
+- If you add a feature it should be documented.
+
+- Also, while creating your Pull Request on GitHub, please write a description
+ which gives the context and/or explains why you are creating it.
+
+Thank you very much!
+
+
+Running the tests
+-----------------
+
+The Markdown parser classes are tested with [PHPUnit](https://phpunit.de/). For each test case there is a set of files in
+the subfolders of the `/tests` folder. The result of the parser is tested with an input and an output file respectively
+where the input file contains the Markdown and the output file contains the expected HTML.
+
+You can run the tests after initializing the lib with composer(`composer install`) with the following command:
+
+ vendor/bin/phpunit
+
+To create a new test case, create a `.md` file a`.html` with the same base name in the subfolders of
+the `/tests` directory. See existing files for examples.