[ZH] Add `Changing the artist or title` and cleanup `Livestreaming osu!`

[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

• A /wiki/Guides/Changing_the_artist_or_title/zh.md
• M /wiki/Guides/Livestreaming_osu!/zh.md (Formatting fix)