Implement a REST API returning "Hello, Will" on the endpoint GET /hello

[alesr]

As a Backend Developer, I want to implement a REST API that returns "Hello, Will" on the endpoint GET /hello in the "books-crud" repository so that I can demonstrate the ability to create and deploy a basic API endpoint.

Acceptance Criteria:

• A REST API is implemented in the "books-crud" repository that listens for incoming HTTP requests on the endpoint GET /hello.
• When a request is received on the GET /hello endpoint, the API returns a response with a status code of 200 and a body containing the string "Hello, Will".
• The API is deployed and accessible to clients via a public URL (no authentication needed).
• The repository README is updated to include documentation on how to access the API and make requests to the GET /hello endpoint.
• Unit tests are implemented.