feat: add browser esm build

[antfu]

Follow up #109

• Inlined join and dirname so it no longer relays on path in browser build.
• New ESM build for browser under ./dist/index.browser.mjs where you would need to import explicitly with full URL when using in the browser.

/cc @43081j

[antfu]

Tests failed due to the missing of dark-vs.json and light-vs.json, which I supposed is not introduced in this PR. Do you have any clue about how would that happen? (also seems like the tests are not triggered for the commits on the master branch)

[antfu]

Ah, should be this one 840a6cf

[43081j]

looks good, i tried it in chrome and it works well.

just so i understand, what is it that bundles the dependencies into the output file? its right, i just wondered where that happens as the two rollup bundles look identical except the browser one has terser, so is it terser which causes it to be one single-file bundle?

[antfu]

@43081j the difference is that the external options which controls whether the deps should be bundled. terser is used for minification.

[43081j]

yeah i thought so, thats why i was confused :D i didn't notice the external part! thanks for pointing that out