Update to use fourwire and root_group for CP 9 compatibility

Author: prcutler

README.rst

@@ -105,6 +105,7 @@ Usage Example
     import time
     import board
     import displayio
+    import fourwire
     import adafruit_acep7in
 
     displayio.release_displays()
@@ -116,7 +117,7 @@ Usage Example
     epd_reset = board.D11
     epd_busy = board.D12
 
-    display_bus = displayio.FourWire(
+    display_bus = fourwire.FourWire(
         spi, command=epd_dc, chip_select=epd_cs, reset=epd_reset, baudrate=1000000
     )
 
@@ -133,7 +134,7 @@ Usage Example
         t = displayio.TileGrid(pic, pixel_shader=pic.pixel_shader)
         g.append(t)
 
-        display.show(g)
+        display.root_group = g
 
         display.refresh()
 

examples/acep7in_simpletest.py

@@ -11,6 +11,7 @@
 import time
 import board
 import displayio
+import fourwire
 import adafruit_acep7in
 
 displayio.release_displays()
@@ -22,7 +23,7 @@
 epd_reset = board.D11
 epd_busy = board.D12
 
-display_bus = displayio.FourWire(
+display_bus = fourwire.FourWire(
     spi, command=epd_dc, chip_select=epd_cs, reset=epd_reset, baudrate=1000000
 )
 
@@ -39,7 +40,7 @@
     t = displayio.TileGrid(pic, pixel_shader=pic.pixel_shader)
     g.append(t)
 
-    display.show(g)
+    display.root_group = g
 
     display.refresh()