Make the CI fail when the docs syntax is invalid

[lbalmaceda]

Changes

Adds a step to build the docs in the CI, failing if something if the syntax is wrong. This will help enforce good docs, now that we publish them to Readthedocs.

References

List of options: https://www.sphinx-doc.org/en/master/man/sphinx-build.html

• -W converts warnings to errors
• --keep-going will not stop in the first error, useful to get the complete list of errors.
• -n will verify broken links and references
• -a runs the docs generation task even when the source code hasn't changed

Testing

• This change adds unit test coverage
• This change adds integration test coverage
• This change has been tested on the latest version of the platform/language or why not

Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All existing and new tests complete without errors