replace cpx code with generic gemma analogout

Introducing_CircuitPlaygroundExpress/CircuitPlaygroundExpress_AnalogOut.py

@@ -1,15 +0,0 @@
-# CircuitPlaygroundExpress_AnalogOut
-# hook up ground an A0 to a voltmeter or scope
-# to watch the voltage rise!
-from analogio import AnalogOut
-import board
-import time
-
-aout = AnalogOut(board.A0)
-
-while True:
-  # Count up from 0 to 65535, with 64 increment
-  # which ends up corresponding to the DAC's 10-bit range
-  for i in range (0,65535,64):
-    aout.value = i
-    time.sleep(0.01)

Introducing_Gemma_M0/Gemma_AnalogOut.py

@@ -1,4 +1,4 @@
-# Gemma IO demo - analog output
+# CircuitPython IO demo - analog output
      
 from analogio import AnalogOut
 import board