Upgrade megalinter to v6

oxsecurity/megalinter#1592

.github/workflows/mega-linter.yml

@@ -35,11 +35,11 @@ jobs:
       - name: MegaLinter
         id: ml
         # You can override MegaLinter flavor used to have faster performances
-        # More info at https://megalinter.github.io/flavors/
-        uses: megalinter/megalinter/flavors/documentation@v5
+        # More info at https://megalinter.io/latest/flavors/
+        uses: oxsecurity/megalinter/flavors/documentation@v6.15.0
         env:
           # All available variables are described in documentation
-          # https://megalinter.github.io/configuration/
+          # https://megalinter.io/latest/configuration/
           VALIDATE_ALL_CODEBASE: true # Set ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }} to validate only diff with main branch
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # ADD YOUR CUSTOM ENV VARIABLES HERE TO OVERRIDE VALUES OF .mega-linter.yml AT THE ROOT OF YOUR REPOSITORY