Port react storybook to this repo

[b5]

We’re big fans of storybook, and would love to get a storybook implemented in this repo. This would give us an environment to experiment with & extend components & a place to iterate on different flows.

This PR starts simple: introduce storybook to our codebase with a simple story around our existing Button component. After this PR the next step would be to turn out a Stylesheet component as a story to track styling across the app.

@jlwaugh previously implemented this for us on our prior repo: qri-io/frontend. This time around we need to do it with typescript. The storybook implementation in that repo should serve as a guide.

PR1: Steps to complete:

• follow https://storybook.js.org/docs/guides/guide-react/
  • manually add the storybook dep to our dev dependencies
  • add an entry to package.json scripts, as outlined in the guide
  • follow the steps for adding a simple button, but use our button component instead
• add a new section to README.md called "Qri Storybook" linking to what the storybook is, and give quick steps to open the storybook
• open PR & 🎉

[chriswhong]

Storybook is in! Closing