Merge pull request #24 from FoamyGuy/fix_readme_example

update readme example reference to fourwire

Author: dhalbert

README.rst

@@ -37,14 +37,15 @@ Usage Example
 
     import board
     import displayio
+    import fourwire
     from adafruit_ssd1351 import SSD1351
 
     spi = board.SPI()
     tft_cs = board.D5
     tft_dc = board.D6
 
     displayio.release_displays()
-    display_bus = displayio.FourWire(spi, command=tft_dc, chip_select=tft_cs, reset=board.D9)
+    display_bus = fourwire.FourWire(spi, command=tft_dc, chip_select=tft_cs, reset=board.D9)
 
     display = SSD1351(display_bus, width=128, height=128)