ci: add ShellCheck workflow for shell script linting

- Introduced a GitHub Actions workflow to run ShellCheck on all .sh files
- Ensures shell scripts follow best practices and common standards
- Helps catch syntax errors, quoting issues, and style problems early

This improves code quality and enforces consistency in shell script contributions.

Signed-off-by: Srikanth Muppandam <[email protected]>

Author: smuppand

.github/workflows/shellcheck.yml

@@ -0,0 +1,15 @@
+name: Shell Lint
+
+on: [pull_request, push]
+
+jobs:
+  shellcheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install ShellCheck
+        run: sudo apt-get install -y shellcheck
+      - name: Run ShellCheck
+        run: |
+          find . -name '*.sh' -exec shellcheck {} +
+