Extend the readme.

The readme has only shown the status of the CI server, but there are
more important things that should be part of the readme.

Author: stefanbirkner

README.md

@@ -1,3 +1,62 @@
 # System Rules
 
-[![Build Status](https:/travis-ci.org/stefanbirkner/system-rules.svg?branch-master)](https://travis-ci.org/stefanbirkner/system-rules)
+[![Build Status](https://travis-ci.org/stefanbirkner/system-rules.svg?branch=master)](https://travis-ci.org/stefanbirkner/system-rules)
+
+System Rules is a collection of JUnit rules for testing code which uses
+`java.lang.System`.
+
+
+## Installation
+
+System Rules is available from
+[Maven Central](http://search.maven.org/).
+
+    <dependency>
+      <groupId>com.github.stefanbirkner</groupId>
+      <artifactId>system-rules</artifactId>
+      <version>1.7.0</version>
+    </dependency>
+
+Please don't forget to add the scope `test` if you're using System
+Rules for tests only.
+
+
+## Usage
+
+System Rules' documentation is stored in the `gh-pages` branch and is
+available online at
+http://stefanbirkner.github.io/system-rules/index.html
+
+
+## Contributing
+
+You have three options if you have a feature request, found a bug or
+simply have a question about System Rules.
+
+* [Write an issue.](https://github.com/stefanbirkner/system-rules/issues/new)
+* Create a pull request. (See [Understanding the GitHub Flow](https://guides.github.com/introduction/flow/index.html))
+* [Write a mail to [email protected]](mailto:[email protected])
+
+
+## Development Guide
+
+System Rules is build with [Maven](http://maven.apache.org/). If you
+want to contribute code than
+
+* Please write a test for your change.
+* Ensure that you didn't break the build by running `mvn test`.
+* Fork the repo and create a pull request. (See [Understanding the GitHub Flow](https://guides.github.com/introduction/flow/index.html))
+
+Fishbowl supports [Travis CI](https://travis-ci.org/) for continuous
+integration. Your pull request will be automatically build by Travis
+CI.
+
+
+## Release Guide
+
+* Select a new version according to the
+  [Semantic Versioning 2.0.0 Standard](http://semver.org/).
+* Set the new version in the `Installation` section of this readme.
+* `mvn release:prepare`
+* `mvn release:perform`
+* Create release notes on GitHub.