Adding CONTRIBUTING.md (#79)

Co-authored-by: ThomasLandauer <thomas@landauer.at>

Author: TavoNiievez

CONTRIBUTING.md

@@ -0,0 +1,83 @@
+# How to Contribute
+
+First of all: Contributions are very welcome!
+
+**Does your change require a test?**
+
+## No, my change does not require a test
+So you're going to make a small change or improve the documentation? Hey, you rock!
+
+- Either just edit [`Symfony.php`](https://github.com/Codeception/module-symfony/blob/master/src/Codeception/Module/Symfony.php) on GitHub's website.
+- Make sure to add a descriptive title and add an explanation for your changes.
+
+> :bulb: You can also create a *fork* and *cloning it* on your local machine, as explained in the next section.
+
+## Yes, my change requires a test
+
+So you're going to add or modify functionality? Hey, you rock too!
+
+You can use our prepared [Codeception/symfony-module-tests](https://github.com/Codeception/symfony-module-tests).
+It is a minimal (but complete) Symfony project, ready to run tests.
+
+### 1. Edit locally
+
+- Go to [Codeception/symfony-module-tests](https://github.com/Codeception/symfony-module-tests) and fork the project.
+   Then follow the installation instructions.
+   <br/>
+- Edit the module's source code in the `vendor/codeception/module-symfony/src/Codeception/Module/Symfony.php` file.
+   <br/>
+- If you created a new method, you can test it by adding a test in the `tests/Functional/SymfonyModuleCest.php` file.
+> :bulb: Be sure to Rebuild Codeception's "Actor" classes (see [Console Commands](https://codeception.com/docs/reference/Commands#Build)):
+> ```shell
+> vendor/bin/codecept clean
+> vendor/bin/codecept build
+> ```
+> With this, your IDE will be able to recognize and autocomplete your new method.
+
+- Then, run the tests with the `vendor/bin/codecept run Functional` command.
+
+### 2. Confirm your changes
+
+- If you are satisfied with your changes, the next step is to fork [Codeception/symfony-module](https://github.com/Codeception/module-symfony).
+   In your terminal, go to another directory, then:
+   ```shell
+   # Clone the repo
+   git clone https://github.com/YourUserName/module-symfony.git
+
+   # Create a new branch for your change
+   cd module-symfony
+   git checkout -b new_feature
+   ```
+> :bulb: If you've created a fork before, make sure to [sync the changes](https://stackoverflow.com/a/7244456).
+
+- Copy the changes from the `Symfony.php` of the test project to the `src/Codeception/Module/Symfony.php` file on your Module's fork.
+   <br/>
+- Commit:
+   ```shell
+   git add --all
+   git commit --message="Briefly explain what your change is about"
+   git push --set-upstream origin new_feature
+   ```
+
+### 3. Create a Pull Request
+
+- In the CLI output, click on the link to `https://github.com/YourUserName/module-symfony/pull/new/new_feature` to create a Pull Request through GitHub.com.
+
+Now wait for feedback on your Pull Request. If all is fine and gets merged...
+
+### 4. Send a Test
+
+- In the test project (`symfony-module-tests`), create a test with the same name as your new method in `tests/Functional/SymfonyModuleCest.php`, following alphabetical order.
+
+- Run the tests with `vendor/bin/codecept run Functional` command.
+
+- Commit:
+    ```shell
+    git checkout -b new_test
+    git add --all
+    git commit --message="Describe what feature you are testing"
+    git push --set-upstream origin new_test
+    ```
+
+- In the CLI output, click on the link to `https://github.com/YourUserName/symfony-module-tests/pull/new/new_test` to create a Pull Request through `GitHub.com`.
+  Don't forget to add a link to the module's Pull Request you created.