Adding a small "Getting Started".
<item name="Introduction" href="index.html" />
<item name="API Documentation" href="apidocs" />
<item name="Download" href="http://www.finmath.net/releases/?C=M;O=D" />
+ <item name="Getting Started" href="gettingstarted.html" />
<item name="Building from Source" href="building.html" collapse="true">
<item name="Maven Build" href="maven.html" />
<item name="Eclipse Project" href="eclipseproject.html" />
