Creating a "What does every button do" bit of documentation

[FallenWyvern]

Created a new header for the navigator ("Usage") with three docs: one for user management, one for library management, and one to explore the administration panel (which is currently, needing expansion).

Each is designed to step users through the function of each feature, as clearly as possible.

[gantoine]

this looks awesome!!

[Copilot]

Pull Request Overview

This PR creates comprehensive user documentation under a new "Usage" section, providing step-by-step guidance for navigating and utilizing key features of RomM. The documentation focuses on explaining the functionality of every button and feature in an accessible manner.

• Added three new usage guides covering user management, library management, and administration
• Created a new "Usage" section in the documentation navigation
• Provided detailed explanations of roles, permissions, and interface elements

Reviewed Changes

Copilot reviewed 4 out of 8 changed files in this pull request and generated 5 comments.

File	Description
docs/Usage/UserManagement.md	Documents user creation, role management, and user removal processes
docs/Usage/LibraryManagement.md	Comprehensive guide to library interface, game/platform management, and all menu functions
docs/Usage/Administration.md	Overview of administration panel features and user profile management
docs/Navigation.md	Adds the new Usage section to the documentation navigation structure

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