[Readme] Using the extension with Behat and Slim.

Author: pavlakis

README.md

@@ -1,6 +1,75 @@
-# A Behat extension for Slim 3
+# A Behat 3 extension for Slim 3
 
-Based on the [Behat Laravel Extension](https://github.com/laracasts/Behat-Laravel-Extension)
+### This extension was written based on the [Behat Laravel Extension](https://github.com/laracasts/Behat-Laravel-Extension)
 
-*Note* This is an experimental version.
+## Can install it with composer through packagist
+
+```
+ composer install pavlakis/slim-behat-extension
+```
+
+## On your behat.yml file add the extension within the _extensions_ section
+
+```
+    Pavlakis\Slim\Behat: ~
+```
+
+The above is the minimum setup as long as you are using [Akrabat's Slim 3 Skeleton](https://github.com/akrabat/slim3-skeleton) with the default location for `settings.php` at `app/settings.php`
+
+Alternatively, pass the location of the config_file
+
+```
+  config_file: ../../app/configs/settings_test.php
+```
+
+Apart from the config (settings.php) all other parameters are optional, however you can also pass:
+
+```
+      config_file: ../../app/configs/settings_test.php
+      dependencies_file: ../../app/dependencies.php
+      middleware_file: ../../middleware.php
+      routes_file: ../../routes.php
+```
+
+## In your *FeatureContext* file
+
+* Include the _KernelAwareContext_ interface
+* Include the _Pavlakis\Slim\Behat\Context\App_ trait
+* Access the Slim 3 app using `$this->app`
+
+### Feature Context example using Mink
+
+```php
+use Behat\Behat\Context\Context;
+use Behat\Behat\Context\SnippetAcceptingContext;
+
+use Behat\Behat\Hook\Scope\BeforeScenarioScope;
+use Behat\MinkExtension\Context\MinkContext;
+use Pavlakis\Slim\Behat\Context\App;
+use Pavlakis\Slim\Behat\Context\KernelAwareContext;
+
+/**
+ * Defines application features from the specific context.
+ */
+class FeatureContext extends MinkContext implements Context, SnippetAcceptingContext, KernelAwareContext
+{
+    use App;
+
+    /**
+     * Initializes context.
+     *
+     * Every scenario gets its own context instance.
+     * You can also pass arbitrary arguments to the
+     * context constructor through behat.yml.
+     */
+    public function __construct()
+    {
+    }
+}
+
+```
+
+### Accessing your dependencies
+
+`$this->app->getContainer()->get('db')`