build: Switch to Storybook from Styleguidist

[milesj]

to: @stefhatcher @hayes @alecklandgraf

Description

Migrates from Styleguidist to Storybook. This is a proof of concept, let me know your thoughts.

Open questions:

• Should we switch to Storybook?
• Where should the story.tsx files live?
• Should we build our own props table addon?

Motivation and Context

Storybook v5 is really good and offers the following features:

• Responsive checks.
• A11y checks.
• Background switchers.
• Action/console log.
• Themeing.
• Uses TS files for writing examples.
• Story example files can be linted / type checked.
• Possibility to use Happo/Percy for visual diffing.

However, things it does poorly compared to Styleguidist.

• Ugly/useless prop tables (inferred from TS types). (Implemented a custom addon)
• No live example editing (does support knobs, which is quite involved).

Testing

TBD

Screenshots

Checklist

• My code follows the style guide of this project.
• I have updated or added documentation accordingly.
• I have read the CONTRIBUTING document.

[milesj]

@stefhatcher @hayes Finished converting all stories. Can pull the storybook locally and test it.

[milesj]

@alecklandgraf @hayes @stefhatcher This is good to go. Went ahead and wrote my own props addon.

[stefhatcher]

super excited for this! i'll miss the live example editing, but the added benefits are real nice!!!