ci: skip the suite for root markdown changes

A README or ROADMAP edit spent five minutes on a macOS runner building an iOS
app to prove that prose had not broken it.

Scoped to `*.md`, which in a GitHub path filter matches root level only, so the
four root docs are skipped while Docs/**.md and everything under Hutch/ stay
gated. A skip rule that is too broad is how a real change slips through
ungated.

Safe on pull_request because main has no required status checks. A run skipped
by a path filter never reports, so a required check would leave a docs-only PR
waiting on a status that never arrives.

0 files changed, 0 insertions, 0 deletions