react-loading-skeleton 3.0.0 on Node.js NPM

Add the new required CSS import:

import 'react-loading-skeleton/dist/skeleton.css'

Drop Emotion dependency, add CSS file that must be imported
- Dropping Emotion avoids conflicts when multiple Emotion versions are used
  on one page and reduces bundle size
Reimplement SkeletonTheme using React context
- The old SkeletonTheme rendered a <div> which was undesirable in many
  cases. The new SkeletonTheme does not render any DOM elements.
- The old SkeletonTheme did not work if the Skeleton was rendered in a
  portal. The new SkeletonTheme does work in this case.
SkeletonTheme: rename the color prop to baseColor
Convert to TypeScript
Publish code as ES2018 to reduce bundle size
Require React >= 16.8.0
Drop Internet Explorer support

If you need to support Internet Explorer or use an old version of React, please
continue to use react-loading-skeleton v2.

Add many new style-related props to SkeletonTheme
Publish an ES module in addition to a CommonJS module
Add direction prop to support right-to-left animation
Add enableAnimation prop to allow disabling the animation
Add containerClassName prop to allow customizing the container element
Add containerTestId to make testing easier
Add aria-live and aria-busy attributes to the skeleton container to
improve screen reader support

Optimize animation performance:
- The old animation animated the background-position property which made
  the browser repaint the gradient on every frame.
- The new animation animates the transform of a pseudoelement. This
  avoids repaints and results in an observable decrease in CPU usage.
No longer require width and height to be set for the circle prop to
work
Change the default duration from 1.2 s to 1.5 s
Make the default Skeleton base color a tiny bit darker so that the
animation is more visible