first draft

CONTRIBUTING.md

@@ -0,0 +1,21 @@
+Contributing
+============
+
+The Symfony Demo application is an open source project. Contributions made by
+the community are welcome. Send us your ideas, code reviews, pull requests and
+feature requests to help us improve this project. All contributions must follow
+the [usual Symfony contribution requirements](http://symfony.com/doc/current/contributing/index.html).
+
+Web Assets Management
+---------------------
+
+This project manages its web assets in a special way to allow them to work
+without configuring any option, installing any tool or executing any command.
+If your contribution changes CSS styles or JavaScript code in any way, make
+sure to regenerate the `web/css/app.css` and `web/js/app.js` files. To do so,
+uncomment the Assetic blocks in the `app/Resources/views/base.html.twig` and
+execute the following command:
+
+```bash
+$ php bin/console assetic:dump --no-debug
+```