[dsherret]

To be clear for people reading wondering what this is about, this is only a hard recommendation for the public API types. The reason for it, is by adding explicit types to the boundary of your package, the package becomes way faster for users to type check because every user's machine doesn't need to do all the inference work and type check internal types or packages not related to the types. Additionally, it makes the published code more resilient to changes to TypeScript's inference in the future because it's not doing inference. It also becomes way easier to generate documentation for the package (also, the ability to generate .d.ts or bundled .d.ts files without a type checker becomes easier).

Right now, the publish command errors and asks you to fix the issues or bypass it entirely via `--allow-slow-types`. In the future there will be a `--fix` flag to write the explicit types for you.