Add Dependabot and CodeQL support (#4286)

Signed-off-by: Jauder Ho <jauderho@users.noreply.github.com>

Co-authored-by: Adam Warner <me@adamwarner.co.uk>

.github/dependabot.yml

@@ -0,0 +1,17 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    day: saturday
+    time: "10:00"
+  open-pull-requests-limit: 10
+  target-branch: development
+  versioning-strategy: increase