Add documentation for icon_names module

[Lang-Qiu]

Problem Background

The public module icon_names in src/icons/mod.rs lacked documentation, making it harder for users to understand its purpose and usage within the Satty application. This could lead to confusion for contributors and users trying to utilize icon name constants.

Changes Made

• Added a docstring to the icon_names module to clearly describe its purpose: "Module containing generated icon name constants for use in the application."

Verification

• Reviewed the code change to ensure the docstring accurately reflects the module's functionality.
• Built the project to verify no compilation errors were introduced, and the documentation is correctly integrated.

[RobertMueller2]

Since you placed this in draft mode, I'm not sure if you want any comments yet ;)

Good catch, thanks!

Before you submit the PR, please double check the line break style, this PR replaces LF with CRLF on 5 lines. We should only use LF -- and I realise we should have configured that via rustfmt.toml.