chore(build): simplify exports and support nested subpath

[dai-shi]

• simplifies exports in package.json
• supports nested subpath in rollup.config.js
• update node version from 12 to 14

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/pmndrs/jotai/HZ9cZCEbRMRu8TDQsZ8LsWFwDCrP
✅ Preview: https://jotai-git-chore-exports-patten-and-subpath-pmndrs.vercel.app

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit a134985:

Sandbox	Source
React	Configuration
React Typescript	Configuration
React Browserify	Configuration
React Snowpack	Configuration
Next.js	Configuration

[dai-shi]

#697 (comment)
@Thisen Sorry, replaceAll doesn't work, using replace instead.

[dai-shi]

@barelyhuman Does this "exports" look good?

[Thisen]

LGTM

[dai-shi]

@Thisen test failed. 😱

[Thisen]

@Thisen test failed. 😱

@dai-shi, It's fixed now

[barelyhuman]

@dai-shi Seems to be working with the TS Exports, which I guess was my only concern here so yeah it works! 👍🏼

[dai-shi]

Great to hear that. I will create the same PRs in zustand and valtio.