Readme update

Author: Marc Aschmann

README.md

@@ -1,6 +1,21 @@
-Core components
-=========
+# Core components: Reusable flow
+
+## Introduction
+
 [![Build Status](https://travis-ci.org/phpflo/phpflo-core.svg?branch=master)](https://travis-ci.org/phpflo/phpflo-core)
 [![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/phpflo/phpflo-core/badges/quality-score.png?b=master)](https://scrutinizer-ci.com/g/phpflo/phpflo-core/?branch=master)
 [![Code Coverage](https://scrutinizer-ci.com/g/phpflo/phpflo-core/badges/coverage.png?b=master)](https://scrutinizer-ci.com/g/phpflo/phpflo-core/?branch=master)
 [![License](http://img.shields.io/:license-mit-blue.svg)](http://doge.mit-license.org)
+
+If you need reusable components for your next flow, this is the place to find them!
+As you might have guessed, the focus lies on reusability and simplicity, just like the [flow-based programming](http://en.wikipedia.org/wiki/Flow-based_programming) paradigm suggests.
+Contributions welcome!
+
+## Installation
+
+As of now, not needed because it's already included in phpflo/phpflo :-)
+
+Otherwise:
+```shell
+composer require phpflo/phpflo-core
+```