add description to reference sections

docs/pages/reference.rst

@@ -6,29 +6,39 @@ This page contains the API documentation of the ``flipperzero`` module.
 Vibration
 ---------
 
+Control the vibration motor of your Flipper.
+
 .. automodule:: flipperzero._vibro
    :members:
 
 Light
 -----
 
+Control the RGB LED and display backlight of your Flipper.
+
 .. automodule:: flipperzero._light
    :members:
 
 Speaker
 -------
 
+Full control over the built-in speaker module.
+
 .. automodule:: flipperzero._speaker
    :members:
 
 Input
 -----
 
+Make your application interactive with full control over the Flipper's hardware buttons.
+
 .. automodule:: flipperzero._input
    :members:
 
 Canvas
 ------
 
+Write text and draw dots and shapes on the the display.
+
 .. automodule:: flipperzero._canvas
    :members: