Create shellcheck.yml

.github/workflows/shellcheck.yml

@@ -0,0 +1,18 @@
+name: ShellCheck
+
+on:
+  pull_request:
+    paths:
+      - 'tabs/**/*.sh'
+
+jobs:
+  shellcheck:
+    name: Shellcheck
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Run ShellCheck
+      uses: ludeeus/action-shellcheck@master
+      with:
+        scandir: 'tabs'
+        severity: error