* Fix image paths and enhance Japanese translations
I'm a native Japanese speaker and made some small corrections where the wording felt unnatural.
Feel free to ignore any changes if the original wording was intentional.
* Fix typo in README-ja_JP.md
* Update Japanese translation in i18n.json
* Update i18n.json
Change Korean language words from Chinese characters to Hangul
* Update i18n.json
Change Korean language words from Chinese characters to Hangul