Update Docusaurus to 2.0-beta.1

[markerikson]

This PR:

• Updates Docusaurus to 2.0-beta.1
• Actually turns on Webpack 5 caching via Netlify
• Updates the "Why Use This?" page by tweaking a couple infoboxes and deleting the outdated "container components" section

[netlify]

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[github-actions]

Size Change: 0 B

Total Size: 26.6 kB

ℹ️ View Unchanged

Filename	Size	Change
dist/react-redux.js	21.4 kB	0 B
dist/react-redux.min.js	5.26 kB	0 B

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