[visx/visx] namespace all exports

[williaster]

#1043 name-spaced the @visx/xychart package from @visx/visx to an XYChart variable to avoid name conflicts between package exports.

For 2.0.0 we could make this consistent for all packages.

[robsutcliffe]

@williaster I'd be willing to help as a beginner

To clarify: the plan is for all packages exported here to be exported using the package name as a namespace. so for example Annotation would be imported like:
import { Annotation } from '@visx/visx';

and then used like:
<Annotation.LineSubject />

[williaster]

hey @robsutcliffe 👋 , awesome!

yes, you're correct about the plan and the API 💯 We did this initially with the @visx/xychart package, and as you can see in the index file you linked to we used XYChartPackage for the exported name. I think ideally we don't include *Package in the export name, your example of Annotation is could be used across all packages (e.g., XYChartPackage could be updated to XYChart).

[robsutcliffe]

Great. Feel free to assign this to me and I'll add a PR soon

[williaster]

closed by #1121