[Bug]: Link to "Contributing guidelines" is broken

[mikicz]

Actual Behavior

404 - Not found is shown

Expected Behavior

GitHub points to https://github.com/python-openapi/openapi-core/blob/master/CONTRIBUTING.rst

That points to https://openapi-core.readthedocs.io/en/latest/contributing.html

This shows a 404

Steps to Reproduce

Follow the link https://github.com/python-openapi/openapi-core/blob/master/CONTRIBUTING.rst

OpenAPI Core Version

N/A

OpenAPI Core Integration

N/A

Affected Area(s)

docs

References

No response

Anything else we need to know?

No response

Would you like to implement a fix?

None