Expose 'googlesheets4_quiet' in the function API, or advertise it better

[MichaelChirico]

I was trying to figure out how to quiet the sheets output messages:

✔ Reading from ${BOOK_TITLE}.

✔ Range ''${SHEET_TITLE}''.

Naturally, I checked ?read_sheet to figure this out, expecting a quiet= option.

I found none, and might have concluded it's not possible to do so, but I doggedly chased down the source code, clicking through 3 definitions before finding it's possible:

googlesheets4/R/range_speedread.R

Lines 94 to 100 in 55cd9fd

	msg <- glue(
	"
	Reading from {.s_sheet {x$name}}<<sheet_msg>><<range_msg>>.",
	.open = "<<",
	.close = ">>"
	)
	gs4_bullets(c(v = msg))

googlesheets4/R/utils-ui.R

Lines 131 to 140 in 55cd9fd

	gs4_bullets <- function(text, .envir = parent.frame()) {
	quiet <- gs4_quiet() %|% is_testing()
	if (quiet) {
	return(invisible())
	}
	cli::cli_div(theme = gs4_theme())
	# TODO: fix this: when I switched from cli::cli_bullets() to
	# cli::cli_inform(), my custom bullet styling was lost (suppressing colour)
	cli::cli_bullets(text, .envir = .envir)
	}

googlesheets4/R/utils-ui.R

Lines 80 to 82 in 55cd9fd

	gs4_quiet <- function() {
	getOption("googlesheets4_quiet", default = NA)
	}

It would be nice to have this directly as an option; otherwise, one of the @examples could set this option to demonstrate it.