[docs] Markdownlint sweep for existing recipe/schema docs

[alanshurafa]

Summary

Fixes pre-existing markdownlint failures across unrelated recipes and schemas so the repository-wide lint check can pass independently of feature PRs.

This follows the same dedicated cleanup pattern as prior markdownlint sweeps in #161 and #215.

Scope

• Formatting-only markdownlint fixes across 8 existing files
• No changes to the six active ExoCortex port contribution folders
• No content or behavior changes intended

Verification

• npx -y markdownlint-cli2@0.22.0 --config .github/.markdownlint.jsonc **/*.md #node_modules -> 0 errors across 142 files

Why this PR exists

The six open upstream PRs #217-#222 are blocked by the repo's whole-tree lint CI check, which reports pre-existing markdownlint errors outside those PRs' touched folders. Keeping this as a separate cleanup PR avoids mixing unrelated formatting changes into feature contributions.

[alanshurafa]

Refreshing upstream checks after fork-side readiness cleanup.

[justfinethanku]

Refreshed this branch against current main, resolved the stale markdownlint conflicts, and added the missing dashboards/open-brain-dashboard-next/README.md MD028 fix that was blocking newer PRs.

Local verification from the refreshed PR checkout:

npx --yes markdownlint-cli2 --config .github/.markdownlint.jsonc "**/*.md" "#node_modules"

Result:

Linting: 177 file(s)
Summary: 0 error(s)

GitHub now reports the PR as mergeable; it is still blocked on normal review requirements.

[alanshurafa]

Thanks @justfinethanku for refreshing this against main, clearing the stale markdownlint conflicts, and adding the missing MD028 fix — much appreciated. Confirmed mergeable against current main.

[justfinethanku]

Reviewed the diff as a mechanical markdownlint cleanup. Changes are doc-only, CI is green, and this clears the shared lint blocker for the Alan PR queue.