Add a stroke to the text when using type "number"

[felippehsk]

Hi!
Thank you for this amazing R package! To help with the visualization when using type = 'number' it would be good to have a black stroke around the numbers, such as the one we can add to the shapes when outline = TRUE.

I could not find an easy implementation using graphics::text. For labels within ggplot, THIS function can be used. Something similar would be amazing!