Fixed formatting

Co-authored-by: Hugo van Kemenade <[email protected]>

Author: radarhere

docs/releasenotes/9.3.0.rst

@@ -31,7 +31,7 @@ Allow default ImageDraw font to be set
 
 Rather than specifying a font when calling text-related ImageDraw methods, or
 setting a font on each ImageDraw instance, the default font can now be set for
-all future ImageDraw operations.
+all future ImageDraw operations::
 
     from PIL import ImageDraw, ImageFont
     ImageDraw.ImageDraw.font = ImageFont.truetype("Tests/fonts/FreeMono.ttf")