Update links for smoother navigation

[AmirLavasani]

Fixes #46

Pull Request Explanation:

This PR addresses the issue of navigation disruption in the README.md file. Currently, the links at the beginning of the document are absolute URLs, causing the page to reload when clicked. To enhance user experience and improve navigation flow, I've updated these links to use anchor links only.

Changes Made:

• Replaced absolute URLs with anchor links.
• Previous Format: [Link Text](https://github.com/zhanymkanov/fastapi-best-practices#1-project-structure-consistent--predictable)
• Updated Anchor Format: [Link Text](#1-project-structure-consistent--predictable)

Impact:

• Smoother navigation within the document.
• Eliminates page reloads when clicking on links.
• This change ensures a more seamless browsing experience for users accessing the README.md file.

[zhanymkanov]

That's awesome! Thank you.