feat: The error message should be printed whenever there is an error in `render_single_qmd()`

[ColinFay]

Description

The error message is not printed here :

  # try rendering qmd and warn user if successful / fail
  tryCatch(
    expr = {
      quarto_render(
        input = qmd,
        metadata = c(metadata, list(`extract-media` = img_dir)),
        output_format = output_format,
        quiet = quiet
      )
      return(TRUE)
    },
    error = \(error_message) {
      cli_alert_danger("Failed to render {qmd}, cleaning and existing")

      # throw an error with original error message
      return(FALSE)
    }
  )

It should be printed, maybe if debug is TRUE?