Re-add a CI build integration to pull requests

[JoshuaKGoldberg]

Since moving this from JoshuaKGoldberg to typescript-eslint, there hasn't been a CI integration such as CircleCI or Azure Pipelines. There used to be a CircleCI integration set up

• CircleCI: I don't have permissions to set it up on this repository
• Pipelines: looks like caching is still experimental, so builds wouldn't be as snazzy as they were on CircleCI

FYI @JamesHenry - any chance we could stick on Circle? 🕺

[JamesHenry]

Hey @JoshuaKGoldberg I just made you an admin of the repo, hopefully that gets you what you need?

[JoshuaKGoldberg]

Thanks! It's working on CircleCI. https://circleci.com/gh/typescript-eslint/tslint-to-eslint-config/tree/master

I don't see why it's not showing up in PRs as an integration, so I'll wait a bit before investigating...