chore: add example for newcomers

[AgustinRamiroDiaz]

Description

This PR introduces an official examples/ directory and includes a sample "Prop Drilling Refactor" challenge. This serves as both a template for creating future interview patterns and a quick way for developers/contributors to test the environment locally.

What's Changed

• Added examples/prop-drilling: Created a complete, working interview pattern that tests a candidate's ability to refactor a prop-drilled architecture using the React Context API.
• Updated tsconfig.json: Added the examples directory to the "include" array so that absolute path aliases (like @/interviews/types) resolve correctly within the examples folder without throwing TypeScript errors.
• Updated README.md: Added a new "Testing the Environment with Examples" section outlining the steps for users to copy the example challenge into the src/interviews folder and test the application shell.

How to Test

1. Pull down this branch.
2. Run cp -r examples/prop-drilling src/interviews/.
3. Start the server with npm start.
4. Navigate to http://localhost:8080 (or your configured port).
5. Verify the Context API Refactor challenge appears on the home screen and launches successfully.