Update HISTORY.txt

Author: jap

HISTORY.rst

@@ -18,6 +18,7 @@ History
 * Uncap the required Python version, to avoid problems detailed in https://iscinumpy.dev/post/bound-version-constraints/#pinning-the-python-version-is-special (`#275 <https://github.com/python-attrs/cattrs/issues/275>`_)
 * Fix `Converter.register_structure_hook_factory` and `cattrs.gen.make_dict_unstructure_fn` type annotations.
   (`#281 <https://github.com/python-attrs/cattrs/issues/281>`_)
+* Expose all error classes in the `cattr.errors` namespace. Note that it is deprecated, just use `cattrs.errors`. (`#252 <https://github.com/python-attrs/cattrs/issues/252>`_)
 
 22.1.0 (2022-04-03)
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