Emit TypeScript type definitions

[jubnzv]

It would be beneficial to have the ability to automatically generate TypeScript type definitions from Melange, as is possible in ReScript.

This would enable users to gradually integrate Melange into a TypeScript project, eventually allowing a complete rewrite.

Otherwise, as far as I understand, the user must manually write TS type definitions for the generated JS and maintain them when making changes to the Melange project.

[davesnx]

Related #916

[anmonteiro]

This is a duplicate of #916