Added release notes

Author: radarhere

docs/releasenotes/12.1.0.rst

@@ -41,6 +41,20 @@ TODO
 API additions
 =============
 
+FreeTypeFont.has_characters
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+``ImageFont.FreeTypeFont`` has a new method for checking whether characters are present
+in the font or not. :py:meth:`.ImageFont.FreeTypeFont.has_characters` will return
+``True`` if all of the characters in the given string are available::
+
+    from PIL import ImageFont
+    font = ImageFont.truetype("Tests/fonts/FreeMono.ttf")
+    font.has_characters("Test")  # True
+    font.has_characters(b"Test")  # True
+    font.has_characters("\u2022")  # True
+    font.has_characters("\u0000")  # False
+
 Specify window in ImageGrab on macOS
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^