xlarge and xxlarge missing ?

[JeromeDeBoysere]

Hello,

I can not find the .xlarge and .xxlarge classes in your flexboxgrid.css ( https://github.com/fclaussen/Flexbox-Framework/blob/master/dist/css/flexboxgrid.css )

Two more things:

• Is it possible to have an human-readable CSS file ? :)
• Is it possible to mention when the classes .medium, .large, .xlarge and .xxlarge are applied (in pixels) ? I had to convert each "min-width" (64.0625em) to know the size in pixels ;(

Thanks a lot for your great job !