Translated ja-JP and ja-KS language files to Sharkey specifications.

Created by: Amelia

What

Translated ja-JP.yml and ja-KS.yml language files to Sharkey specifications.

Why

Because the language file was in Misskey notation, not Sharkey notation.

Additional info (optional)

Checklist

• Read the contribution guide
• Test working in a local environment
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests