feat: Add a demo vite app

[csandman]

This PR adds a new demo app that can be found at ./demo. This is to aid in the local development of the package (something that has been a long time coming). Along with this, some contribution guidelines have been added, so hopefully this will encourage new contributors!

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One other nice add-on this PR includes is adding a new action, pkg.pr.new. With this action, any future pull requests will now trigger a preview release which can be installed by anyone. It also generated a preview StackBlitz which can be used to easily test any changes.

This was previously included with a similar GitHub action from CodeSandbox. However, with their new basic tier restrictions, their version was no longer feasible.

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One final change, is that I added the GitHub stylized alert block quotes to the readme. This is something I only recently discovered, and it makes the Readme look much nicer. They look like this:

Note

This is a note.

[github-actions]

📊 Package size report   0.1%↑

File	Before	After
package.json	2.9 kB	4%↑3.0 kB
README.md	47.4 kB	0.3%↑47.5 kB
Total (Includes all files)	267.5 kB	0.1%↑267.8 kB
Tarball size	59.8 kB	0.04%↑59.8 kB

Unchanged files

File	Size
dist/index.d.mts	19.9 kB
dist/index.d.ts	19.9 kB
dist/index.js	16.2 kB
dist/index.js.map	72.7 kB
dist/index.mjs	14.8 kB
dist/index.mjs.map	72.7 kB
LICENSE.md	1.1 kB

_{🤖 This report was automatically generated by pkg-size-action}

[pkg-pr-new]

Open in Stackblitz • chakra-react-select-demo

yarn add https://pkg.pr.new/[email protected]

commit: e896665