[ZH] Update `Beatmap editor/Song setup`

[CloneWith]

Self-check

• [x] The changes are tested against the contribution checklist
• [x] (translations only) The changes are reviewed on GitHub by a fluent speaker

Changed files

• M /wiki/Client/Beatmap_editor/Song_setup/zh.md
• Link /wiki/Beatmap/Difficulty/zh.md
• Link /wiki/Beatmap/Genre_and_language/zh.md
• Link /wiki/Beatmap/Primary_metadata_source/zh.md
• Link /wiki/Client/Beatmap_editor/zh.md