Add GitHub Actions workflow

.github/workflows/shellcheck.yml

@@ -0,0 +1,25 @@
+name: ShellCheck
+
+on:
+  push:
+    branches:
+      - main
+      - develop
+
+  pull_request:
+
+jobs:
+  shellcheck:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Repository auschecken
+        uses: actions/checkout@v4
+
+      - name: ShellCheck installieren
+        run: sudo apt-get update && sudo apt-get install -y shellcheck
+
+      - name: ShellCheck ausführen
+        run: |
+          shellcheck bootstrap.sh
+          find install -name "*.sh" -exec shellcheck {} \;