Documentation left

Things to document:

- [x] `keyword: "isFile"` error when multipart ajv plugin is not present.

- [x] Document that kita global root is required.

Self import of operationIds: _(Will change when ESM support arrieves)_

- [ ] Route operationId re-exports cannot be used in the first tick of the nodejs process in order to avoid circular
dependencies. They must be used in the second tick or imported directly from the routes/... file.
(`await Runtime.ready`)
- [ ] Build only dts runtime inside single-thread builds to prevent circular dependencies to messing up return type of
routes using another routes.