[docs] fix broken internal link (/docs/installation.md)

- Removed the `/docs` part and the `.md` part from the link. 
- Tested with `bundle exec jekyll serve`.
- Working correctly now.

docs/maven-example.md

@@ -14,7 +14,7 @@ Let's deploy a Springboot Java application with Docker Compose file using Fabric
 * Linux or MacOS or Windows
 * JDK 1.7+ - [JDK Quick Installation Guide](http://openjdk.java.net/install/)
 * Maven 3.x+ - [Maven Installation Guide](http://www.baeldung.com/install-maven-on-windows-linux-mac) 
-* Kompose - [Kompose Installation Guide](/docs/installation.md)
+* Kompose - [Kompose Installation Guide](/installation)
 
 __1. Clone the example project from GitHub__
 ```bash