This page is for the badly named LCD Display plugin.
It is for the Rapsi only because it uses the GPIO.
It uses a standard HDD44780 compliant display.
In my case I used a OLED from Maplin OLED 20x2

Here is the connection diagram for the LCD (I’ve just discovered Fritzing)
Because I used an OLED display I don’t need any connections for the display contrast or +V or Ov for the LED power