first add files

lib/Crypto/Hash/SHAKE256.pyi

@@ -0,0 +1,13 @@
+from typing import Union, Optional
+
+Buffer = Union[bytes, bytearray, memoryview]
+
+class SHAKE256_XOF(object):
+    oid: str
+    def __init__(self,
+                 data: Optional[Buffer] = ...) -> None: ...
+    def update(self, data: Buffer) -> SHAKE256_XOF: ...
+    def read(self, length: int) -> bytes: ...
+    def new(self, data: Optional[Buffer] = ...) -> SHAKE256_XOF: ...
+
+def new(data: Optional[Buffer] = ...) -> SHAKE256_XOF: ...