Combine CNC cutting pages

content/02_cnc_cutting.md

content/03_cnc_cutting_vinyl.md

content/03_electronics_production.md

content/04_3d_printing_scanning.md

content/05_electronics_design.md

content/06_cnc_machining.md

content/07_embedded_programming.md

content/08_molding_and_casting.md

content/09_input_devices.md

content/10_output_devices.md

content/11_machine_week.md

content/12_interfaces.md

content/13_networking.md