Ship types with the npm package

[Uzlopak]

Context

• node version: not applicable
• module version: 5.0.0
• environment (e.g. node, browser, native): not applicable
• any other relevant information:

What problem are you trying to solve?

Follow up for #334

It would be nice, if the typings would be shipped with the code. I know you decided to maintain the code by the community of definetly typed, as stated in #342 (comment) . But if it is with the package, we could easily refer them in typings, which are using them too, like in @fastify/simple-oauth2.

See fastify/help#900 (comment)

At fastify we ship the typings with the npm package, and test the typings with tsd. Pull Requests in fastify packages need corresponding typing changes if applicable. This way, you could ensure, that the typings are always in sync with the code.

3 years have passed since the last decision regarding this topic, so maybe you reconsider it.

Do you have a new or modified API suggestion to solve the problem?

I will provide a simple PR.