Fastapi-xml

+ migrated to fastapi 0.113. Changes are inspired by stan-janssen
+ added `py.typed` for mypy support

What's Changed
* update to pydantic v2 by cercide in https://github.com/cercide/fastapi-xml/pull/7

New Contributors
* va-h made their first contribution in https://github.com/cercide/fastapi-xml/pull/8
* cercide made their first contribution in https://github.com/cercide/fastapi-xml/pull/7

**Full Changelog**: https://github.com/cercide/fastapi-xml/compare/1.0.0b1...1.1.0

- include xml schema using add_openapi_extension
- doctests added
- unittests added
- coverage checked
- mypy checked
- tox added
- pre-commit added
- docs added