Remove depreciated .show from library

adafruit_portalbase/graphics.py

@@ -56,7 +56,7 @@ class GraphicsBase:
 
         # set the default background
         if default_bg is not None:
-            self.display.show(self.splash)
+            self.display.root_group = self.splash
             self.set_background(default_bg)
 
         gc.collect()

examples/portalbase_simpletest.py

@@ -11,6 +11,7 @@ See MatrixPortal, MagTag, and PyPortal libraries for more examples.
 
 
 import board
+import displayio
 from adafruit_pyportal import PyPortal
 
 # Set a data source URL
@@ -20,7 +21,7 @@ TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html"
 pyportal = PyPortal(url=TEXT_URL, status_neopixel=board.NEOPIXEL)
 
 # Set display to show REPL
-board.DISPLAY.show(None)
+board.DISPLAY.root_group = displayio.CIRCUITPYTHON_TERMINAL
 
 # Go get that data
 print("Fetching text from", TEXT_URL)