Add synced linter configs to fix Spellcheck on v0.59

[brooke-hamilton]

Description

The Spellcheck workflow on v0.59 fails on every PR (e.g. #1926) with a CSpell configuration error, not spelling errors:

Configuration Error: Failed to read config file:
  "/home/runner/work/docs/docs/.github/linters/.cspell.yml"
CSpell: Files checked: 0, Issues found: 0 in 0 files with 1 error.

Root cause

v0.59 was synced with the reusable radius-project/.github spellcheck workflow (__spellcheck.yml), which runs cspell against .github/linters/.cspell.yml. The workflow and root .cspellignore came across, but the companion .github/linters/.cspell.yml config file was never added — so cspell has no config to read and errors out.

Fix

Cherry-pick of edge commit 4d50ee7e ("chore(sync): synced file(s) with radius-project/.github (#1935)"), which adds the shared linter configs under .github/linters/, including .cspell.yml. This restores parity with edge, where spellcheck already passes. The change is purely additive (.github/linters/ did not exist on v0.59).

Validation

Ran the exact CI command locally on this branch:

cspell lint --config .github/linters/.cspell.yml --no-progress --dot "**/*.md"
→ CSpell: Files checked: 316, Issues found: 0 in 0 files.
→ EXIT CODE: 0

Notes

• The other linter configs added (.markdownlint*, .prettierrc.yml, .shellcheckrc, .yamllint.yml) are dormant on v0.59 (no workflow references them yet) and are included to keep parity with edge for the next file sync.
• Dependabot PR ci(deps-dev): bump tar from 7.5.15 to 7.5.19 in /docs #1926 that surfaced this was targeted at v0.59; the same change passes on edge. This PR fixes v0.59 for all PRs regardless.

Co-authored-by: Copilot App [email protected]

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None