Update linkchecker base URL to GitHub Pages

Author: hohwille

.github/workflows/linkchecker.yml

@@ -15,7 +15,7 @@ jobs:
         run: sudo apt-get install w3c-linkchecker
       - name: start check
         run: |
-          checklink -r -s -b https://devonfw.com  | tee output.txt
+          checklink -r -s -b https://devonfw.github.io  | tee output.txt
       - name: parse check output
         run: |
           output=$(cat output.txt)