feat: updated zhCN & zhTW related

[Yarnus]

Summary

First of all, thank you for building EllesmereUI. I really appreciate how clean, minimal, and lightweight this addon is. I have been recommending it to players around me because it offers a polished UI experience without feeling bloated.

Some of those players are not equally comfortable with English, so I drafted this PR to improve Simplified Chinese and Traditional Chinese support. I hope this can make the addon easier to use for more Chinese-speaking players.

Changes

• Added Simplified Chinese locale coverage for existing static UI strings.
• Added Traditional Chinese locale coverage for the same strings.
• Updated the language selector labels for zhCN and zhTW to use native display names.

Notes

The existing locale engine already supports zhCN and zhTW, so this PR focuses only on improving translation coverage and the visible language labels.

[EllesmereGaming]

i had already accepted someone elses translations so i had to manually merge this as there were too many conflicts, but I added it. thank you!! if i missed anything please rebase and submit a new PR.