Update part-03.md

[orun-sunny]

Type request as Observable for clarity and type safety

Description

By declaring the variable type, developers can better understand the asynchronous nature of the service methods and get improved IDE support (autocomplete, type inference, etc.).

Checklist

• I fully tested it as developer
• I tested the create and update flows to ensure everything works as expected

I verified that the modal closes, the form resets, and the list refreshes after submission

How to test it?

Open the form modal (e.g., "Add Book" or "Edit Book").

Fill in the form and submit.

Ensure the form triggers the proper API call (create or update).

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[sumeyyeKurtulus]

Hello,

Thanks for this PR! The line const request: Observable<any> = ... is actually not needed. The inference of TypeScript already correctly types request as Observable<BookDto>, making the explicit Observable<any> redundant and less specific.

We will close this PR for now. Thanks again for your contribution!