chore: import upstream snapshot with attribution

docs/api/hanlp/utils/index.md

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+# utils
+
+Utilities.
+
+```{toctree}
+io_util
+```

docs/api/hanlp/utils/io_util.md

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+# io_util
+
+```{eval-rst}
+
+.. currentmodule:: hanlp.utils
+
+.. automodule:: hanlp.utils.io_util
+	:members:
+
+```