Add fabricating instructions

[Kreyren]

These are missing and it's not a good practice to guestimate them (was a real pain to figure these out for teres pcbs for me):

• BoardSpec: (IPC 6012 Class 2, IPC 6012 Class 3, IATF16949, ISO 13485, custom standard, etc..)
• Material Type: (minimal, optimal and maximal TG for the FR4 board, halogen?, CTI?, special material?)
• Material Thickness (0.2~3.2mm)

• Min track/spacing: 3/3mm ~ 8/8mil
  

• Min hole size: (0.15 ~ 1.0mm)

• Min Via hole size/diameter

• Surface Finish (ENIG?)

• Outer Copper Weight/Finished copper (0 oz to 20 oz of Cu)

• Inner Copper Weight

• Board Outline Tolerance

• Via Covering (Tented, Epoxy Filled & Untented, Plugged, Epoxy Filled & Capped, Copper paste Filled & Capped)

Ideally in a form of minimal to maximal recommended, options that should not be used etc.. (i want to make custom PCBs with edge plating and high outer weight so that would help a lot ^-^)

* Options taken from own (no buried or blind vias) + local + EU + foreign
* For details to these options refer to jlcpcb or pcbway's instant quote forms.