Add CodeQL workflow configuration (#20)

Author: JamieMagee

.github/workflows/codeql.yml

@@ -0,0 +1,37 @@
+name: CodeQL
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+  schedule:
+    - cron: "15 3 * * 1" # https://crontab.guru/#15_3_*_*_1
+
+permissions: {}
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      security-events: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@6bc82e05fd0ea64601dd4b465378bbcf57de0314 # v4.32.1
+        with:
+          languages: go
+
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@6bc82e05fd0ea64601dd4b465378bbcf57de0314 # v4.32.1
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@6bc82e05fd0ea64601dd4b465378bbcf57de0314 # v4.32.1