Proposal to Use Doxygen-Awesome to Modernize Doxygen's Look

[Andres-Salamanca]

I added the stylesheet from the Doxygen-Awesome project. This project provides a highly customizable CSS stylesheet designed to freshen up Doxygen's default style.

• Modern Design: Offers a cleaner and more user-friendly design compared to the default style.
• Customizability: The stylesheet allows further adjustments to align with specific branding or aesthetic preferences.

Here’s a preview of how Doxygen could look with this stylesheet applied:

The stylesheet supports further tweaks through CSS variables, such as:

--primary-color
--primary-dark-color
--primary-light-color

--page-background-color
--page-foreground-color
--page-secondary-foreground-color

and more others : Customization.

[dietmarkuehl]

The change looks good to me. I think may be reasonable to include an appropriate SPDX-License-Identifier: <license-identifier> into all files, especially as their license is different from the other files.

[dietmarkuehl]

It seems review-dog is upset about trailing spaces in some of the files (and I should look at the issue with the "github token").

[Andres-Salamanca]

I added the SPDX-License-Identifier: MIT License to the CSS and JS files and used prettier to automatically fix whitespace issues. But some whitespace-related changes are still being flagged