Add a new version to a PCB project.

PCB project versions allow you to specify variants and changes to the gerber data, bill of
materials, or placement data. Once you have created a new PCB version, you can then upload new
files or create a new bill of materials under that PCB version.

By default the new version is a clone of the version in the URL: its files, bill of materials,
placement data, and specifications are copied. Pass target=blank to create an empty version
instead.