Update defining-your-first-asset.md

docs/dagster-university/pages/dagster-essentials/lesson-3/defining-your-first-asset.md

@@ -66,4 +66,4 @@ Your first asset, which you’ll name `taxi_trips_file`, will retrieve the yello
 
 That’s it - you’ve created your first Dagster asset! Using the `@asset` decorator, you can easily turn any existing Python function into a Dagster asset.
 
-Questions about the `-> None` bit? That's a Python feature called type annotations. In this case, it's saying that the function returns nothing. You can learn more about type annotations in the [Python documentation](https://docs.python.org/3/library/typing.html). We highly recommend using type annotations in your code to make it easier to read and understand.
+**Questions about the `-> None` bit?** That's a Python feature called **type annotation**. In this case, it's saying that the function returns nothing. You can learn more about type annotations in the [Python documentation](https://docs.python.org/3/library/typing.html). We highly recommend using type annotations in your code to make it easier to read and understand.