Document how to interpret and report Quality Receipts

[gavinjudd]

Goal

Add a compact, source-free walkthrough showing contributors how to read a Quality Receipt and decide whether to file a false positive, false negative, or missing-coverage report.

Scope

• Use synthetic receipt values only.
• Explain repository/commit/path identity, bounded line range, parser version, observed metric, applicability, attribution status, and public URL.
• Show that unsupported languages and insufficient attribution lower coverage rather than quality.
• Link the four relevant issue forms and docs/ADDING_A_LANGUAGE.md.
• Avoid employment, intelligence, total-ability, or personal-worth language.

Acceptance

• Documentation works for a first-time contributor and a nontechnical reporter.
• No raw source, private path, token, or reviewer identity appears.
• Commands are valid in the documented shell.
• pnpm community:check and pnpm format:check pass.