Add trailing slash to PR preview URL

Author: m-aciek

.github/workflows/update.yml

@@ -46,7 +46,7 @@ jobs:
           repo: ${{ github.event.repository.name }}
           owner: ${{ github.repository_owner }}
           pr: ${{ github.event.number }}
-          url: "https://${{ github.repository_owner }}.github.io/${{ github.event.repository.name }}/${{ github.ref_name }}"
+          url: "https://${{ github.repository_owner }}.github.io/${{ github.event.repository.name }}/${{ github.ref_name }}/"
           message: "📊 Dashboard preview 📊:"
       - name: Debug index.html if pull request
         if: github.event_name == 'pull_request'