Migrate from JavaScript to TypeScript

[HonkingGoose]

I see that the code uses JavaScript. The main Renovate repo uses TypeScript.

Do we want to migrate from JavaScript to TypeScript?

[maxbrunet]

The repo uses a tech stack as close as possible to what was already in @renovatebot, but I have struck a middle ground between the simplicity of https://github.com/renovatebot/renovate-approve-bot/ and the complexity of https://github.com/renovatebot/renovate. I think the overhead of TypeScript is not worth it here. The product itself is just this index.js of ~100 lines 😅

[HonkingGoose]

@rarkins and @viceice What do you think?

[viceice]

Would be great for code safety, but i've no time to work on this. 🤷‍♂️

[rarkins]

I'm fine to leave as is