Review `locales/docs/typst-docs.toml` - reduce term

[Myriad-Dreamin]

Description

Continue reviewing the locales/docs/typst-docs.toml.

• The reduce term should be translated to "规约", according to the Wikipedia.
• The reduce term should be translated to "规约" conditionally. You can only translate it to "规约" if the word is about dictionaries.
• find all reduce in the file, and annotate the them by specific syntax mentioned in the copilot instructions. If there is mistranslation, please fix them.
• again, please following the copilot instructions, including but not limited to:
  • only the first term in a translation text is annotated.
  • also add or update the reduce term in the docs/terms.toml file.