Add Khmer Language Support for Admin Interface (i18n)

[Leap-Chanvuthy]

Description:

I would like to contribute Khmer language support (Khmer / Khmer-Cambodia) to Payload CMS. This feature will enable Cambodian users to use the admin interface in their native language and improve accessibility for the region.

Proposed Features:

• Add a kh.json (or kh-KH.json) language file for the admin panel.
• Translate core UI elements such as menus, buttons, settings labels, and error messages.
• Ensure correct date, number, and currency formatting (DD/MM/YYYY, Cambodian Riel ៛).
• Verify proper layout rendering for Khmer text in the admin dashboard.

Benefits:

• Expands Payload CMS usability to Cambodian developers and businesses.
• Demonstrates Payload’s commitment to global i18n support.
• Provides a foundation for future plugins and starter kits targeting the Cambodian market.

Additional Notes:
I would love guidance on best practices for contributing i18n features and any conventions to follow for language files and testing.

Thank you!

Chanvuthy Leap