RFC: should `chroma` be exported?

[Vindaar]

I just thought whether it might be a good idea to export the chroma module in plotly.nim. If we did that we don't have to import it in all examples where we use the Color type. That might make it a little more user friendly, too.

[brentp]

seems so. that was an oversight. I'm not sure how active chroma is and thought maybe it's not needed, but as long as it's a dep it should be exported.