Colour jll's differently

[tfiers]

depgraph_image(:Plots,stdlib=false) (but jll=true):

So not same as stdlib. But, uhm yellow? orange?
A colour not in the gradient of :)

• time_imports: dataviz (encode load-time graphically) #86

[tfiers]

Doing this 'makes sense', it's consistent, because: stdlib is faded, and can be filtered, and has a function (is_in_stdlib). Jll can be filtered, has a function.. but no graphical distinction; yet.
Will give user intuition for what's filtered out and what the counts mean from

• Heuristic to auto-hide stdlib if too many #80

eg: JLLWrappers is not a _jll. but will be filtered out with :ignore -- but not with :hide. hm or mayb it will: no orphans