Feat/1253 add kannada readme translation

[Nandeeshps-coder]

Summary

This PR adds Kannada language support to the Lingo.dev README translations as requested in issue #1253.

Changes Made

• ✅ Added Kannada language code "kn" to i18n.json targets array
• ✅ Created complete Kannada translation in readme/kn.md
• ✅ Maintained consistency with existing translation structure
• ✅ Included proper Kannada translations for technical terms

Testing

• [x] File structure validation
• [x] JSON syntax validation
• [x] Content completeness check
• [x] Language links integration
• [x] File size consistency with other translations (8,591 bytes)

Files Changed

• i18n.json - Added "kn" to targets
• readme/kn.md - New Kannada translation (8,591 bytes)
• 6 existing README files - Updated language links

The translation follows the same structure and quality standards as existing language versions, making Lingo.dev more accessible to Kannada-speaking developers.

Closes #1253