message: docs: release notes for the v9.1.7 release
diff: +<a name="9.1.7"></a>
  +## [9.1.7](https://github.com/angular/angular/compare/9.1.6...9.1.7) (2020-05-13)
  +
  +This release contains various API docs improvements.
  +
  +
  <a name="9.1.6"></a>
  ## [9.1.6](https://github.com/angular/angular/compare/9.1.5...9.1.6) (2020-05-08)
  