Update example workflow

GitHub-Actions.md

@@ -9,6 +9,8 @@ GitHub action for running ShellCheck differentially. New findings are reported d
 ```yaml
 name: Differential ShellCheck
 on:
+  push:
+    branches: [ main ]
   pull_request:
     branches: [main]
 
@@ -16,18 +18,25 @@ permissions:
   contents: read
 
 jobs:
-  test:
+  lint:
     runs-on: ubuntu-latest
 
+    permissions:
+      # required for all workflows
+      security-events: write
+
+      # only required for workflows in private repositories
+      actions: read
+      contents: read
+
     steps: 
       - name: Repository checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
       - name: Differential ShellCheck
-        uses: redhat-plumbers-in-action/differential-shellcheck@v3
+        uses: redhat-plumbers-in-action/differential-shellcheck@v5
         with:
-          severity: warning
           token: ${{ secrets.GITHUB_TOKEN }}
 ```