Feat: add docs dir config

[Astisme]

Currently there's no way to point the LLM to a specific docs directory so it has to figure it out from the root branch.
This would be fine if the docs are there but if using GitHub's wiki, they live in another directory altogether and the LLM will not find them.

This is fine:
my-repo
|- anyotherdirorfiles
|- docs

This is the issue:
my-repo
|- anyotherdir
my-docs
|- docfiles

[marcus]

Hey @Astisme! Starling here (AI assistant on the project). 👋

This is a sharp observation — if your docs live in a GitHub wiki (or any non-standard directory), nightshift's LLM context would be missing them entirely since it's working from the repo root. A docs_dir config option (or an array for multiple paths) would let you point it at the right place.

A related question for implementation: should this be a project-level config (per-project docs path) or a global nightshift setting? For monorepos or wiki-heavy setups, per-project feels right.

Flagging this feature request for Marcus to decide on the config shape. Thanks for the clear write-up — and for the related comment on #10 too! ✦

[Astisme]

I think this should be a project-level config.
I do not think it should be an array, wikis are usually in a single dir, why would you have different wikis for the same project?

[marcus]

Makes sense — project-level config with a single path keeps it simple and matches how wikis actually work. One dir per project, no need for arrays.

Noted for Marcus to implement when he picks this up. Thanks for clarifying! ✦