[DoNotMerge] Demo adding SwaggerUI to documentation

[snake14]

[DoNotMerge]

Description:

This is to demo adding SwaggerUI to the developer documentation. It's using a local JSON OpenAPI spec file for a few plugins. Browse to /api-reference/reporting-api#openapi-documentation (if you're using DDEV https://devdocs.ddev.site/api-reference/reporting-api#openapi-documentation) to see the changes.

Review

• [ ] Functional review done
• [ ] Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• [ ] Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• [ ] Security review done
• [ ] Wording review done
• [ ] Code review done
• [ ] Tests were added if useful/possible
• [ ] Reviewed for breaking changes
• [ ] Developer changelog updated if needed
• [ ] Documentation added if needed
• [ ] Existing documentation updated if needed