Add renderDT(outputArgs=), remove doc dependency on deprecated Shiny funcs

We're transitioning toward removing `shiny::dataTableOutput` and `shiny::renderDataTable` and having them shim their DT equivalents. (see https://github.com/rstudio/shiny/issues/3986) Neither the addition of `outputArgs` nor the removal of the `@inheritParams` are urgently needed, just thought I'd do this while I was thinking of it.