Font import helpers

[cpsievert]

This PR ports font_google(), font_link(), and font_face() from {bslib} into {sass} so that any {sass} project can more easily import font files when declaring font-family Sass variables. The one catch is that you must use them inside named list variable declarations (as shown below). Note that by default font_google() will download, cache, and serve font files locally (so end users don't need an internet connection to render the font), but you can also import any remotely hosted web font with font_link()/font_face().

library(htmltools)

scss <- list(
  list("font-variable" = font_google("Pacifico")),
  list("body {font-family: $font-variable}")
)

hello <- tags$body(
  "Hello",
  tags$style(sass(scss))
)

if (interactive()) {
  browsable(hello)
}