chore: Cleanup wording (#20)

Author: chriswblake

README.md

@@ -20,7 +20,7 @@ In this exercise, you will:
 ### How to start this exercise
 
 > [!IMPORTANT]
-> This exercise may not explain the Copilot basics that were introduced in the [Getting Started with Copilot](https://github.com/skills/getting-started-with-github-copilot) exercise. If you are new to Copilot we recommend starting with that one.
+> This exercise assumes basic knowledge of [GitHub Copilot](https://github.com/features/copilot). If you are unfamiliar, we recommend the [Getting Started with Copilot](https://github.com/skills/getting-started-with-github-copilot) exercise.
 
 Simply copy the exercise to your account, then give your favorite Octocat (Mona) **about 20 seconds** to prepare the first lesson, then **refresh the page**.