This reverts commit 091b8d58b3502a99b3bfbec9db457c92cc736beb, reversing
changes made to 9b2ca9cf8e.

- Handle invalid choice in Examples.TryGetValue
- Add exit condition for choice "Exit"
- Display a rule before executing example
- Clear console after each iteration

📝 This change refactors the TestRunner.cs file. It handles invalid choices in Examples.TryGetValue, adds an exit condition for the choice "Exit", displays a rule before executing an example, and clears the console after each iteration.