Instructions CLI argument to generate custom documentation.

[richie-rk]

Currently the output is always a beginner-friendly tutorial. It would be useful to let users guide the document style, for example, a feature doc from a user perspective, an architecture overview, or an API reference.

My suggestion is to add a --instructions flag that passes custom instructions into each LLM prompt, similar to how --language works.

python main.py --repo <url> --instructions "Write a feature document from a user perspective"

When omitted, behavior is unchanged. I have a working implementation in my fork. I'm happy to open a PR if this fits the project direction.

[richie-rk]

Quick note from testing: The CLI argument works best with instructions that adjust tone and focus, for example.
"Use precise technical terminology," "Avoid jargon and use plain language," "Focus on user-facing features," and "Keep explanations concise and skip analogies." Instructions that contradict the existing tutorial framing (like "Write wiki pages") produce a hybrid output as abstraction selection shifts correctly, but chapter bodies still lean tutorial style.