Publishing ESM

[43081j]

Most consumers are running in node (without a bundler) so this has been fine so far as CJS

However, it is the only one of the many alternatives that doesn't ship modern modules. So it would be good to solve that

To avoid having to ship a dual package (which would mean doubling the package size), my suggestion is basically:

• maintain a 1.x branch which ships as CJS
• maintain main which ships as ESM
• all changes go into both branches until a majority of consumers are using the ESM version

Id be happy to help out if needed