FontAwesome Scaling in Toolbar Icons

[coatless]

From @ute in #175

RE: Scaling font-awesome symbols

TODO (if this seems sensible): adjust size of buttons.
this is probably possible by css (em units?)

[coatless]

Regarding re: output text

ideally, font-scale set in code should influence output, too.
this should also be applicable to quarto-r-code cells
maybe file an feature request with quarto? code cells
are really small by default. Of course, you want to cram
a lot of code on slides ;-)

From @ute in #172 (comment) we have:

If I want to make it smaller temporarily, for example I have too much code on a slide and my students have good eyes, I can wrap it in a div that shrinks font size :-). If I want it to be smaller globally, I would override font size in pre -style.

Just realizing that this last paragraph makes a comment obsolete that I made in my PR, about asking quarto to make a similar font-size chunk option 😊

So, I'm removing the upstream note. Still need to address the FA symbol.