Add noise generated terrain

[Doprez]

This is a very simple example of using FNL to generate terrain and could easily be expanded on if you want to add multiplied/additive noise on top of this example.

Since I used the majority of this code for the actual mesh gen I figured it may fit into this repo as an added option.

[johang88]

Nice, I started doing something similar some time ago but this looks much nicer :D