message: fix(doc): fix aot.md
  Spelling correction.
diff: The compilation process described on the [official Angular2 website](https://angular.io/docs/ts/latest/cookbook/aot-compiler.html)
  -Note that you also have to include bootstrap CSS from the official Bootrstrap site or Bootstrap CDN in your index.html HEAD section.
  +Note that you also have to include bootstrap CSS from the official Bootstrap site or Bootstrap CDN in your index.html HEAD section.
  ## 1. Install `ngx-bootstrap`
  