Adding a new normalizer that strips accents by removing combining (#416)

* Adding a new normalizer that strips accents by removing combining

characters in unicode strings.

* Adding Node bindings

+ better normalizer impl.

* Doc comment -> Regular comment.

bindings/python/py_src/tokenizers/normalizers/__init__.py

@@ -9,6 +9,7 @@ NFKC = normalizers.NFKC
 Sequence = normalizers.Sequence
 Lowercase = normalizers.Lowercase
 Strip = normalizers.Strip
+StripAccents = normalizers.StripAccents
 Nmt = normalizers.Nmt
 Precompiled = normalizers.Precompiled
 

bindings/python/py_src/tokenizers/normalizers/__init__.pyi

@@ -99,6 +99,12 @@ class Strip(Normalizer):
     def __init__(self, left: bool = True, right: bool = True) -> Normalizer:
         pass
 
+class StripAccents(Normalizer):
+    """ StripAccents normalizer """
+
+    def __init__(self) -> Normalizer:
+        pass
+
 class Nmt(Normalizer):
     """ Nmt normalizer """