Add Arabic (ar-AR) translation

[mamgad]

Changes

• Added Arabic translation (README-ar-AR.md) to the doc/translations directory
• Added Arabic translation link to the main README.md in alphabetical order
• Implemented proper RTL support using HTML dir tags
• Maintained LTR formatting for code blocks, commands, and technical content

Implementation Details

• Used <div dir=rtl> for Arabic text sections
• Used <div dir=ltr> for code blocks, links, and technical content
• Followed the same structure as other RTL translations (e.g., Persian)
• Preserved all technical terms, commands, and URLs unchanged
• Maintained consistent formatting with other translations

Checklist

• Translation follows project structure
• RTL/LTR handling implemented correctly
• Technical terms remain unchanged
• Links and references are working
• Added to main README.md translations list

[MachiavelliII]

I hope that the maintainers will merge this pull request as soon as possible.