message: feat(update): Update to angular 9
  BREAKING CHANGE: Probably no breaking changes, but bumping to 4.0.0.
diff: @@ -15,12 +15,18 @@ See [Demo](https://ng-select.github.io/ng-select) page.
  | Angular| ng-select|
  | ------|:------:|
  +| >=9.0.0 <10.0.0 | v4.x |
  | >=8.0.0 <9.0.0 | v3.x |
  | >=6.0.0 <8.0.0 | v2.x |
  | v5.x.x | v1.x |
  ---
  +perf(pencil): remove graphiteWidth option
  +
  +BREAKING CHANGE: The graphiteWidth option has been removed.
  +The default graphite width of 10mm is always used for performance reasons.
  +
  Table of contents
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