Add automated PR review comments based on Vint linter (#410)

.github/workflows/vint.yml

@@ -8,11 +8,10 @@ jobs:
     steps:
     - name: Checkout
       uses: actions/checkout@master
-    - name: Set up Python
-      uses: actions/setup-python@v1
+    - name: Run vint with reviewdog
+      uses: reviewdog/action-vint@v1.0.1
       with:
-        python-version: 3.7
-    - name: Setup dependencies
-      run: pip install vim-vint
-    - name: Run Vimscript Linter
-      run: vint .
+        github_token: ${{ secrets.github_token }}
+        reporter: github-pr-review
+
+