Define the importable files through `exports` property in `package.json`

[sequba]

Description

Publint reports for all files in /es/ directory:

pkg.module is used to output ESM, but pkg.exports is not defined. As NodeJS doesn't read pkg.module, the ESM output may be skipped. Consider adding pkg.exports to export the ESM output. pkg.module can usually be removed alongside too. (This will be a breaking change)

We can fix it by adding the exports property to package.json.

It should probably be done together with #1086

Warning: this change might be considered breaking.

HOT team did a similar task in https://github.com/handsontable/handsontable/pull/7403 & https://github.com/handsontable/handsontable/pull/8875/files#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519

Links

• https://handsoncode.slack.com/archives/C4PV4S33Q/p1673602200151429 (internal discussion)
• #1086