refactor(esm): converted the package to esm-only

[csantos1113]

BREAKING CHANGE: semantic-release/git is now an ES Module. Fixes #490

I tried to follow the same exact approach taken in semantic-release/error#249 - but let's see if it works 🤞

[csantos1113]

not really sure how to update these 👀

[travi]

I tried to follow the same exact approach taken in semantic-release/error#249 - but let's see if it works 🤞

the error package is one of our simpler projects, so it may not provide enough examples for converting this whole plugin. you can find the PRs for the conversion of the other core plugins linked in the initial definition of semantic-release/semantic-release#2133, which are a bit more thorough.

i did kick off the execution of the verification workflow so you could see feedback from that to see how things currently stand. i recommend running the verification locally to get a faster feedback loop than you'll be able to get being dependent on a maintainer to kick off that workflow execution.

[travi]

side note: we are working on updating our workflows to enable a simpler way to execute the same verification locally as happens in the ci workflows. if you would like to help us convert this project's workflow as a separate PR first, that might help make your local development exerience a bit simpler for this project. you can find a couple of examples of that progress here:

• test(structure): consolidated all verification under the test script while also enabling isolated execution semantic-release#2964
• test(structure): consolidated all verification under the test script github#719