message: docs: correct minor typo
  PR Close
diff: @@ -2398,7 +2398,7 @@ So when you call `createComponent()`, the `TestBed` compiles implicitly.
  That's not a problem when the source code is in memory.
  But the `BannerComponent` requires external files
  -that the compile must read from the file system,
  +that the compiler must read from the file system,
  an inherently _asynchronous_ operation.
  If the `TestBed` were allowed to continue, the tests would run and fail mysteriously
  