Can't specify output directory with `quarto_render()`

There is no parameter for quarto_render() that allows the user to set a desired output directory when rendering a .qmd document.

In rmarkdown::render() this functionality is seen with the output_dir parameter.

The use case I have for setting an output directory, other than it being generally useful, is rendering a .qmd template from an R package. Currently, quarto_render() attempts to write the output document to the location of the template in the R package directory. This therefore limits the utility of quarto templates in R packages. I would like to see quarto_render() to work as rmarkdown::render() does, which allows users to set an output directory for the destination of a rendered template.

Start at the quarto_render() entry point and compare its arguments and output handling with rmarkdown::render(), especially output_dir. Trace how a .qmd template path is passed to rendering, then verify that specifying an output directory places the rendered document there rather than beside the package template.