ColorConverter: fix a docstring

Author: jepler

shared-bindings/displayio/ColorConverter.c

@@ -39,7 +39,7 @@
 //| class ColorConverter:
 //|     """Converts one color format to another."""
 //|
-//|     def __init__(self, *, colorspace: Colorspace=Colorspace.RGB888, dither: bool = False) -> None:
+//|     def __init__(self, *, input_colorspace: Colorspace=Colorspace.RGB888, dither: bool = False) -> None:
 //|         """Create a ColorConverter object to convert color formats.
 //|
 //|         :param Colorspace colorspace: The source colorspace, one of the Colorspace constants