disable Protel extensions and plot the username of the gerber file

[Shackmeister]

Hi All

Is there any good reason why Protel extensions was used? They are generally considered obsolete and JLCPCB works perfectly fine the normal gerber extensions.

Secondly I changed the plotting to use the (optionally) custom names of the layers.
This way the name can indicate the purpose of the layer.

Thanks for a great plugin

[bennymeg]

Because this is what they are asking to use.
https://jlcpcb.com/help/article/how-to-generate-gerber-and-drill-files-in-kicad-8
I think it can cause problems down the rode on some edge cases if it is not properly supported by them