message: docs: add note about relative redirect
diff: @@ -21,6 +21,22 @@ Since the library is still unstable **and because we want feedback** on bugs and
  .flat()
  ```
  - _resolving_(`router.resolve`) or _pushing_ (`router.push`) a location with missing params no longer warns and produces an invalid URL, but throws an Error instead
  +- Relative children path `redirect` are not supported. Use named routes instead:
  + ```js
  + // replace
  + let routes = {
  + path: '/parent/',
  + children: [{ path: '', redirect: 'home' }, { path: 'home' }],
  + }
  + // with
  + let routes = {
  + path: '/parent/',
  + children: [
  + { path: '', redirect: { name: 'home' } },
  + { path: 'home', name: 'home' },
  + ],
  + }
  + ```
  #### Improvements
  