Provide detailed Pin Layout instead of raw board

[fcartegnie]

• I'm submitting a ...
  • bug report
  • [ x ] feature request

Because pictures are useless when you have the board in front of you

https://github.com/fossasia/pslab-hardware/blob/master/docs/pin_layouts/PSLab_Pin_Layout.pdf

[thewasif]

@fcartegnie Do you mean, we should add this picture instead of the boards??