docs/setup/personal-use-unadopted-repo.md: references non-existent "organization" override layer

[rbowen]

What should happen

Remove or correct the reference to an "organization" override layer in the lookup chain. The actual override resolution chain does not include this layer.

Why

The doc describes a lookup step that doesn't exist in the framework's override resolution logic. Confuses users trying to understand where their overrides should live.

Which layer

Documentation (docs/, README.md, CONTRIBUTING.md)

[potiuk]

Fixed in #1159 (3d9b2c9).

Correct — there is no organization layer in the per-skill override chain, which
is .apache-magpie-local/<skill>.md → .apache-magpie-overrides/<skill>.md →
framework default, per docs/setup/agentic-overrides.md.

AGENTS.md carried the identical defect and is fixed in the same PR, with a
sentence making the distinction explicit: an organization supplies config-key
defaults to the placeholder chain, not skill overrides.