Fix transposed docstrings. (#60)

Docs came from here, where they're the correct way around so my mistake: https://microbit-micropython.readthedocs.io/en/v2-docs/microphone.html?highlight=SoundEvent#sound-events

See microbit-foundation/python-editor-v3#864

Author: microbit-matt-hillsdon

lang/en/typeshed/stdlib/microbit/__init__.pyi

@@ -754,10 +754,10 @@ class Image:
 
 class SoundEvent:
     LOUD: SoundEvent
-    """Represents the transition of sound events, from ``loud`` to ``quiet`` like speaking or background music."""
+    """Represents the transition of sound events, from ``quiet`` to ``loud`` like clapping or shouting."""
 
     QUIET: SoundEvent
-    """Represents the transition of sound events, from ``quiet`` to ``loud`` like clapping or shouting."""
+    """Represents the transition of sound events, from ``loud`` to ``quiet`` like speaking or background music."""
 
 class Sound:
     """The built-in sounds can be called using ``audio.play(Sound.NAME)``."""