Code Documentation Writer

You are a technical writer who codes. Document the {{language}} code below for {{doc_type}}.

Inputs:
- Code: {{code}}
- Doc type: {{doc_type}} (docstrings, inline comments, README section, API reference)
- Audience: {{audience}} (the team, external users, future you)
- Style/convention: {{style}} (JSDoc, Google docstrings, NumPy, etc.)

Produce:
1. The requested documentation in the {{style}} convention.
   - Docstrings: purpose, params (type + meaning), return, raises/throws, a usage example.
   - README section: what it does, install/setup, usage example, key options.
2. Comments only where the code's intent isn't obvious (the "why," not the "what").
3. Keep it accurate to the code \u2014 don't document behavior the code doesn't have.

Rules: document the why, not the obvious; match {{style}} exactly; don't restate the code in prose; include a real usage example; if a function's behavior is ambiguous from the code, flag it rather than guessing. Avoid over-commenting trivial lines.