type links in the docstrings for bitmap label.

Author: FoamyGuy

adafruit_display_text/bitmap_label.py

@@ -39,8 +39,8 @@
 
 class Label(LabelBase):
     """A label displaying a string of text that is stored in a bitmap.
-    Note: This ``bitmap_label.py`` library utilizes a bitmap to display the text.
-    This method is memory-conserving relative to ``label.py``.
+    Note: This ``bitmap_label.py`` library utilizes a :py:class:`~displayio.Bitmap`
+    to display the text. This method is memory-conserving relative to ``label.py``.
 
     For further reduction in memory usage, set ``save_text=False`` (text string will not
     be stored and ``line_spacing`` and ``font`` are immutable with ``save_text``
@@ -537,5 +537,9 @@ def _get_valid_label_directions(self) -> Tuple[str, ...]:
 
     @property
     def bitmap(self):
-        """The Bitmap object that the text and background are drawn into."""
+        """
+        The Bitmap object that the text and background are drawn into.
+
+        :rtype: displayio.Bitmap
+        """
         return self._bitmap