`openAPITS` option doesn't support `output` flag

[TheDutchCoder]

Describe the feature

https://openapi-ts.pages.dev/node#options supports an output flag which we use to have the types available locally and extract manual types from (mainly parameters and request bodies).

It would be good to support this in the module as well, so the generated file doesn't end up in .output during dev time, but actually becomes a file you can commit to your repo.

Additional information

• [ ] Would you be willing to help implement this feature?

Final checks

• [X] Read the contribution guide.
• [X] Check existing discussions and issues.