Merge pull request #1828 from Tony133/docs/mongodb-update

docs(recipes-mongodb): improvement

Author: kamilmysliwiec

content/recipes/mongodb.md

@@ -180,4 +180,4 @@ import { DatabaseModule } from '../database/database.module';
 export class CatsModule {}
 ```
 
-> info **Hint** Do not forget to import the `CatsModule` into the root `ApplicationModule`.
+> info **Hint** Do not forget to import the `CatsModule` into the root `AppModule`.