Update main.yml

Fix VNU download and check

Author: JappeHallunken

.github/workflows/main.yml

@@ -27,9 +27,16 @@ jobs:
         java-package: jre
         check-latest: true
     - name: Download Nu Html Checker
-      run: curl -sSfLO 'https://github.com/validator/validator/releases/download/latest/vnu.jar'
+      run: |
+        curl -sSfL -o vnu.zip \
+          https://github.com/validator/validator/releases/download/20.6.30/vnu.linux.zip
+        unzip vnu.zip
     - name: Run Nu Html Checker to check HTML, CSS and SVG files
-      run: find . -type f \( -name '*.html' -o -name '*.css' -o -name '*.svg' \) -exec java -jar vnu.jar --verbose --also-check-css --also-check-svg --filterpattern '.*skipping . heading level.*|.*bad value .#git. for attribute .rel.*' {} +
+      run: |
+        find . -type f \( -name '*.html' -o -name '*.css' -o -name '*.svg' \) \
+          -exec java -jar vnu-runtime-image/lib/vnu.jar \
+          --verbose --also-check-css --also-check-svg \
+          --filterpattern '.*skipping . heading level.*|.*bad value .#git. for attribute .rel.*' {} +
     - name: Check for obsolete image files
       if: always() && steps.deploy.outcome == 'success'
       run: |