[lengau]

Purpose

Docs-only filter test, stacked on #626. Not intended to merge.

This branch changes docs/README.md and nothing else.

What it tests

Whether starflow's paths filter classifies this change as documentation only,
so the right jobs run:

Job	Expected	Why
filter	runs	always
files (make -k lint-code)	skipped	docs/** and **/*.md are excluded from source-files
docs (make -k docs-lint)	runs	docs-files matches docs/**
linkcheck (make -k docs-linkcheck)	runs	docs-files matches docs/**

This is the "yes-docs, no-code" case, which the pull requests so far have not
covered. docs-lint and docs-linkcheck must both pass, and lint-code must
not appear in the run list at all.

Stacked on this

Source-plus-docs filter test: #632

Related

• ci(lint): improve CI UX when splitting linter jobs #625
• ci: test starbase with starflow's split lint workflow #626
• ci(lint-python): split linting into code, docs, and linkcheck jobs starflow#199