How to configure alpha-numeric displays (P-ROC)

Related Config File Sections
segment_displays:
p_roc:

The P-ROC includes support four alpha-numeric displays (0-3). You can configure them in MPF:

segment_displays:
  display1:
    number: 0
  display2:
    number: 1
  display3:
    number: 2
  display4:
    number: 3