Add missing contributing information

CONTRIBUTING.md

@@ -0,0 +1,36 @@
+## Contributing
+We appreciate any form for contribution you want to make to the project! ExectOS is purely driven by passion, and we
+dedicate any and all available spare time to this project. Contributions of any kind are deerly welcome, but should
+follow the below guidelines.
+
+## Where To Start?
+There is a ton of work to do in ExectOS and we appreciate any help. If you are interested in writing features,
+porting drivers, fixing bugs, writing tests, creating documentation, or helping out in any other way, we would
+love the help.
+
+## Wish List
+If you are looking for a way to contribute, but you are not sure where to start, check our [IDEAS](IDEAS.md) and
+[KNOWN ISSUES](KNOWN_ISSUES.md) pages for suggestions. We try to keep them up to date. You can also check a list of
+[open issues](https://git.codingworkshop.eu.org/xt-sys/exectos/issues). If you find interesting task and you are serious
+about tackling one, feel free to contact us. We will be able to provide a more detailed information and suggestions
+towards getting started.
+
+## Reporting Bugs
+When submitting issues, please take care that the bug report is not a duplicate of an already existing, open issue.
+Please follow the template specified for issues.
+
+## Feature Requests
+ExectOS is currently in early development stage, thus we do not accept feature requests yet. We focus currently on the
+system core components.
+
+## Submissions
+If you want to contribute on the project please fork the repository, and contribute by opening a 
+[Pull Request](https://git.codingworkshop.eu.org/xt-sys/exectos/pulls). There is a pull request template you can use.
+While doing this, please follow few, simple rules:
+ * Provide your real name and e-mail address
+ * Do not commit code that doesn't compile
+ * Test your changes before committing
+ * Always add descriptive log messages
+ * Don't mix formatting changes with code changes
+
+Good luck!