It seems too early to ESM-only packages

[smelukov]

After 0.12, the MF-libraries started using the ESM format. This forces every package and project that uses MF to migrate into ESM. Some of them can't do this for several reasons:

• They use packages that aren't type: "module". Some of these may be upgraded to newer versions (that published as ESM), but some just don't have an ESM.
• Moving into ESM has some costs, such as updating bundlers or their configuration (some of which is not easy, especially for large enterprise projects).
• Some of the core MF libraries are CJS (e.g., https://github.com/module-federation/core/blob/master/packages/TypeScript/package.json#L6).

So, it seems too early to start using ESM (or publish packages is ESM-only). For now, it blocks non-ESM projects from getting the latest MF updates, and this is sad.

I would like to propose moving back to CJS or publishing MF-libraries in ESM+CJS format.