[Discussion] Consider ESM-only for v5?

[jcbhmr]

Popular opensource guru sindresorhus has done this sindresorhus/meta#15 https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

I think that this is a good step to avoid the dual package hazard: #37

[mesqueeb]

Don't run too fast because it'll be harder to communicate about how we feel about each change 😅

Discussion regarding to the last post's todos can be continued here: #57
→ Do you want me to address each of your todos with my opinion?

Discussion regarding to the ESM only can be continued here: #55