add one more variant of alef (#3492)

ٱ is also a non  connecting letter

lib/lettering/font_variant.py

@@ -142,7 +142,7 @@ class FontVariant(object):
     def isbinding(self, character):
         # after  a non binding letter a letter can only be in isol or fina shape.
         # binding glyph only have  two shapes, isol and fina
-        non_binding_char = ['ا', 'أ', 'ﺇ', 'آ', 'د', 'ذ', 'ر', 'ز', 'و']
+        non_binding_char = ['ا', 'أ', 'ﺇ', 'آ', 'ٱ', 'د', 'ذ', 'ر', 'ز', 'و']
         normalized_non_binding_char = [normalize('NFKC', letter) for letter in non_binding_char]
         return not (character in normalized_non_binding_char)