fix continuation line - add comment

Author: jerryneedell

adafruit_dht.py

@@ -138,6 +138,9 @@ def measure(self):
         delay_between_readings = 0.5
         if self._dht11:
             delay_between_readings = 1.0
+        # Initialte new reading if this is the first call or if sufficient delay
+        # If delay not sufficient - return previous reading.
+        # This allows back to back access for temperature and humidity for same reading
         if (self._last_called == 0 or
                 (time.monotonic()-self._last_called) > delay_between_readings):
             self._last_called = time.monotonic()