* Allow routes to define some payload config values
* Documentation typo
* Move hapi `payload` config under `body` + additional validations
* Update API docs
* Amend explanation in API docs
* Add stream and buffer types to @kbn/config-schema
* Fixes based on PR feedback:
- Add 'patch' and 'options' to valid RouteMethod
- Add tests for all the new flags
- Allow `stream` and `buffer` schema in the body validations (findings from tests)
* API documentation update
* Fix type definitions
* Fix the NITs in the PR comments + better typing inheritance
* API docs update
* Fix APM-legacy wrapper's types
* Fix KibanaRequest.from type exposure of hapi in API docs
* Move RouterRoute interface back to private + Expose some public docs
* Update @kbn/config-schema docs
