ci: Add super-linter GitHub action

.github/workflows/code-scanning.yml

@@ -1,4 +1,4 @@
-name: "Code Scanning"
+name: Code Scanning
 
 on:
   schedule:

.github/workflows/linter.yml

@@ -0,0 +1,24 @@
+name: Lint Code
+
+on:
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  lint:
+    name: Lint code
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Lint code base
+        uses: github/super-linter@v3
+        env:
+          VALIDATE_DOCKERFILE_HADOLINT: true
+          VALIDATE_BASH: true
+          DEFAULT_BRANCH: master
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.shellcheckrc

@@ -1,6 +1,9 @@
 # Check shellcheck wiki at:
 # https://github.com/koalaman/shellcheck/wiki/SCXXXX
 
+# Allow following non-constant source
+disable=SC1090
+
 # Redirections are performed by the current shell before sudo is started.
 disable=SC2024