validate-markdown,yaml: use Linkspector action

Author: ralfhandl

.github/workflows/validate-markdown.yaml

@@ -29,4 +29,8 @@ jobs:
         run: npx --yes markdownlint-cli2 *.md
 
       - name: Check links in markdown files
-        run: npx --yes @umbrelladocs/linkspector check
+        uses: umbrelladocs/action-linkspector@v1
+        with:
+          reporter: github-check
+          fail_level: any
+          filter_mode: nofilter