Overriding options post-instantiation

[salvamomo]

First of all, thanks for contributing this library.

I have a use case that requires customizing the Content-Type header in certain situations that can only be checked after running render.New(options ...Options). Without that possibility, I'd have to create multiple render instancies, with the different customizations I may need, and then choose between them as needed, which would make the approach suboptimal.

Would you be open to adding support (or accepting contributions for it) for options to be passed to the rendering methods, and not only during instantiation?

[unrolled]

Thanks for reaching out! I'd be happy to accept a contribution to resolve the issue you outlined above.