Add a README.md to Warp-hardware/revB/cad/fusion360/ with screen captures of each of the enclosure designs

[phillipstanleymarbell]

Add a README.md to Warp-hardware/revB/cad/fusion360/ with screen captures of each of the designs from Fusion360 (like the ones in the top-level README.md or something similar/better) to give an idea of what the different enclosures are.