Add Korean (ko-KR) voice pack and update documentation

[siyeongjang]

Summary

This PR adds a complete Korean (ko-KR) voice pack to the EdgeTX SD card sounds.

Details

• Voice files generated using Google Cloud Text-to-Speech (Wavenet-B)
• Audio format: 16-bit PCM, Mono, 32kHz
• Files located in: SOUNDS/ko
• Index files:
  • voices/ko-KR.csv — system phrases
  • voices/ko-KR_scripts.csv — script-specific terms
• Korean section added to README.md with contributor and generation details

Contributor

Created and contributed by @siyeongjang
to improve accessibility for Korean-speaking RC users.

Feedback and suggestions are welcome.

[pfeerick]

Thank you for the contribution! Looks like you have one field too many in ko-KR.csv... the content of "Korean" should be in the "Translation" column. And ko-KR_scripts.csv has missing fields. Run build-checks.py to validate locally. If it doesn't affect your workflow, can you also add double quotes to the fields for consistency. I'm still hoping at some point in the future we can use crowdln or similar for translation, and (and more remote future hope) potentially merge all the languages into one file.

[siyeongjang]

Updated ko-KR.csv and ko-KR_scripts.csv:

• Aligned field structure with voice.csv
• Added 20+ missing entries and formatted all fields with double quotes
• Added missing .wav files under SOUNDS/ko/
• Removed unnecessary .Zone.Identifier files and added ignore rule

All checks now pass locally. Please review when available. Thanks again!

[pfeerick]

Looks good to me... thank you! :)