Add TQFN-20-1EP_4x4mm_P0.5mm_EP2.9x2.9mm
requested to merge Roman3349/kicad-footprint-generator:TQFN-20-1EP_4x4mm_P0.5mm_EP2.9x2.9mm into master
This MR adds a TQFN20 package with a 4x4mm package and a 2.9mm EP.
The dimensions are described here: https://pdfserv.maximintegrated.com/package_dwgs/21-100172.PDF