add bitmap palette property

Author: CedarGroveStudios

cedargrove_waveviz.py

@@ -79,9 +79,14 @@ def __init__(
 
     @property
     def bitmap(self):
-        """The resultant bitmap."""
+        """The resultant bitmap object."""
         return self._bmp
 
+    @property
+    def palette(self):
+        """The resultant displayio.Palette object."""
+        return self._palette
+
     def _plot_wave(self):
         """Plot the wave_table as a bitmap."""
         samples = len(self._wave_table)