build(deps-dev): bump afdocs from 0.19.0 to 0.20.0

Bumps [afdocs](https://github.com/agent-ecosystem/afdocs) from 0.19.0 to 0.20.0.
- [Release notes](https://github.com/agent-ecosystem/afdocs/releases)
- [Commits](agent-ecosystem/afdocs@v0.19.0...v0.20.0)

---
updated-dependencies:
- dependency-name: afdocs
  dependency-version: 0.20.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -12,7 +12,7 @@
     "check:all": "bun run --parallel --no-exit-on-error check:dependencies check:response-examples test:agent-docs docs:validate docs:links"
   },
   "devDependencies": {
-    "afdocs": "0.19.0",
+    "afdocs": "0.20.0",
     "mint": "4.2.808",
     "vitest": "4.1.11"
   },