Revert "Remove the security scan workflow"

.github/codeql/config.yml

@@ -0,0 +1,4 @@
+name: "OpenLayers CodeQL Config"
+
+paths:
+  - src

.github/workflows/security.yml

@@ -0,0 +1,34 @@
+name: "Security Scan"
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+  schedule:
+    - cron: '0 0 * * 0'  # At 00:00 on Sunday
+
+jobs:
+  codeql:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+        with:
+          # Must fetch at least the immediate parents so that if this is
+          # a pull request then we can checkout the head of the pull request.
+          # Only include this option if you are running this workflow on pull requests.
+          fetch-depth: 2
+
+      # Initializes the CodeQL tools for scanning.
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v1
+        with:
+          languages: javascript
+          config-file: ./.github/codeql/config.yml
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v1