Add scripted WDFN-12-1ep, 3x3mm footprint (replace #643)

Script PR: https://github.com/pointhi/kicad-footprint-generator/pull/149 replaces #643

config:

WDFN-12-1EP_3x3mm_P0.45mm_EP1.7x2.5mm:
  device_type: 'WDFN'
  size_source: 'https://www.diodes.com/assets/Datasheets/PAM2306.pdf'
  ipc_class: 'qfn' # 'qfn_pull_back'
  body_size_x:
    minimum: 2.95
    maximum: 3.05
  body_size_y:
    minimum: 2.95
    maximum: 3.05
  lead_width_min: 0.15
  lead_width_max: 0.25
  lead_len_min: 0.35
  lead_len_max: 0.45


  EP_size_x: 1.7
  EP_size_y: 2.5
  EP_num_paste_pads: [2, 2]

  pitch: 0.45
  num_pins_x: 0
  num_pins_y: 6

Screenshot (pad clearance shown as 0.2mm, only for screenshot.):