refs https://github.com/TryGhost/DevOps/issues/50
- we should default to keeping the rule on and so I've excluded lines
that currently use `any` to avoid the need to go and fix them all up
refs https://github.com/TryGhost/DevOps/issues/50
- `react-app` comes from `eslint-config-react-app`, which is a CRA package
- we're moving away from that so this commit switches the linting over
to a more recently updated plugin
- once that was removed, we started using a newer version of
`@typescript-eslint/eslint-plugin`, so there were plenty of
updates/exemptions to make
refs https://github.com/TryGhost/DevOps/issues/50
- this switches the .eslint configs from `node` to `ts`, which is a new
config to support eslint for TypeScript
- also makes minor changes to adhere to these new rules
