Provide a changelog

[jtpio]

Currently, there doesn't seem to be any changelog in the repo.

For example https://github.com/emscripten-forge/mambajs/releases/tag/v0.19.8 does not contain information about the changes it included.

[martinRenou]

For now, one needs to have a look at the diff manually https://github.com/emscripten-forge/mambajs/commits/main/

We should probably have an automatized way to generate changelogs from it.