feat: provide AxesTuple in public location (#419)

Author: henryiii

src/boost_histogram/_internal/axistuple.py

@@ -2,12 +2,14 @@
 from __future__ import absolute_import, division, print_function
 
 from .axis import Axis
+from .utils import set_module
 
 import numpy as np
 
 del absolute_import, division, print_function
 
 
+@set_module("boost_histogram.axis")
 class ArrayTuple(tuple):
     __slots__ = ()
 
@@ -29,6 +31,7 @@ def broadcast(self):
         return self.__class__(np.broadcast_arrays(*self))
 
 
+@set_module("boost_histogram.axis")
 class AxesTuple(tuple):
     __slots__ = ()
     _MGRIDOPTS = {"sparse": True, "indexing": "ij"}

src/boost_histogram/axis/__init__.py

@@ -10,6 +10,7 @@
     StrCategory,
     Boolean,
 )
+from .._internal.axistuple import ArrayTuple, AxesTuple
 from .._core.axis import options
 from . import transform
 
@@ -25,4 +26,6 @@
     "Axis",
     "options",
     "transform",
+    "ArrayTuple",
+    "AxesTuple",
 )