Generate all files needed for PCBA with allpcb

[pierrechevalier83]

I've placed an order for PCBA at allpcb for the bling and there had to be some back and forth with the engineer.

In particular,

• bom and pick and place file should be .xlsx

• the gerber files should contain one layer with the designators for all components. Since I don't want these refs anywhere near the silkscreen layer, consistently mark the refs as visible on F.Fab or B.Fab respectively and make sure gerbers are produced for these layers too.

• [ ] [automation] Generate correct bom file for allpcb

• [ ] [automation] Generate correct pick and place file for allpcb

• [x] [automation] Generate gerbers for F.Fab and B.Fab layers with refs visible

• [ ] [0.2/bling] set the correct visibility for all refs on F.Fab and B.Fab

• [ ] [0.2/compact] set the correct visibility for all refs on F.Fab and B.Fab

• [ ] [0.2/mini] set the correct visibility for all refs on F.Fab and B.Fab

• [ ] [0.2/high] set the correct visibility for all refs on F.Fab and B.Fab

• [ ] [automation] Generate jlcpcp.zip and allpcb.zip with appropriate fabrication files for PCBA for each board