Feature request: compatibility with the {crosstalk} package

[SimonCoulombe]

{crosstalk} allows filtering markers on a leaflet map without needing a full blown shiny server is a great feature of leaflet.

Is it possible to add this feature to rdeck?

https://rstudio.github.io/crosstalk/widgets.html

[anthonynorth]

Would be useful, particularly when combined with #48.