docs(readme): correct yay installation instructions for Arch Linux

[Dexter2038]

Reason: 'yay' is not in official Arch Linux repositories, so sudo pacman -S yay will fail.

Changes:

• Remove sudo pacman -S yay
• Add proper AUR installation steps
• Add base-devel to pacman command, since it's required for AUR builds
• Add --needed flag to avoid reinstalling existing packages

Tested it on my system and it works.

Description

Fix incorrect yay installation instructions for Arch Linux

The current documentation suggests sudo pacman -S yay, which fails because yay is not in the official Arch repositories (it's only available in AUR).

Changes:

• Removed incorrect sudo pacman -S yay line
• Added proper AUR installation: git clone + makepkg
• Added base-devel to system dependencies (required for AUR builds)
• Added --needed flag to avoid reinstalling existing packages

Tested successfully on my Arch Linux system.

Screenshots/videos:

Terminal output verifying the corrected installation steps work:

Checklist:

• [✔️ ] I have read contributing wiki page
• [ ✔️] I have performed a self-review of my own code
• [ ✔️] My code follows the style guidelines
• [ ✔️] My code passes tests