Merge pull request #386 from mpraglowski/contributing-guide

Contributing guide docs

railseventstore.org/source/community.html.md

@@ -11,3 +11,56 @@ Any kind of contribution is welcomed.
 * [Create a new issue](https://help.github.com/articles/creating-an-issue/), assuming one does not already exist.
 * Clearly describe the problem including steps to reproduce when it is a bug.
 * If possible provide a Pull Request with failing test case.
+
+## Prepare a Pull Request
+
+* Fork the [RailsEventStore monorepo](https://github.com/RailsEventStore/rails_event_store)
+
+    ```
+    git clone [email protected]:RailsEventStore/rails_event_store.git
+    cd rails_event_store
+    ```
+
+* Make sure you have all latest changes or rebase your forked repository master branch with RailsEventStore master branch
+
+    ```
+    cd rails_event_store
+    make rebase
+    ```
+
+* Create a pull request branch
+
+    ```
+    git checkout -b new_branch
+    ```
+
+* Implement your feature, don't forget about tests & documentation (to see how to work with documentation files check [documentation's readme ](https://github.com/RailsEventStore/rails_event_store/blob/master/railseventstore.org/README.md)
+
+* Make sure your code pass all tests
+
+    ```
+    make test
+    ```
+
+    You could test each project separately, just enter the project folder and run tests (`make test` again) there.
+
+* Make sure your changes survive mutation testing
+
+    ```
+    make mutate
+    ```
+
+    Will run mutation tests for all projects. The same command executed in specific project's folder will run mutation tests only for that project.
+    Mutation tests might be time consuming, so you could try to limit the scope of mutations to some specific subjects:
+
+    ```
+    make mutate SUBJECT=code_to_mutate
+    ```
+
+    How to specify `code_to_mutate` is described in [Mutant documentation](https://github.com/mbj/mutant#test-selection).
+
+* Don't forget to [create a Pull Request](https://help.github.com/articles/creating-a-pull-request-from-a-fork/). You could do it even if not everything is ready. The sooner you will share your changes the quicker feedback you will get.
+
+## License
+
+By contributing, you agree that your contributions will be licensed under its [MIT License](https://github.com/RailsEventStore/rails_event_store/blob/master/LICENSE).