[v2] wishlist

[pi0]

• ESM-only build
• Drop process shim (in favor unenv v2)
• Rewrite env shim (feat!: improve env polyfill #138, feat: optimized env shim & support object.keys #119)
• Better treeshaking (build: explicitly mark fns to improve tree-shaking #130)

[huseeiin]

suggestion: detect operating system using navigator (i.e. navigator.platform, but its deprecated so we need a better option) in browsers

[huseeiin]

and also, we can detect runtime if user agent is firefox, chrome or safari