feat: Add dependabot configuration

Add dependabot configuration to get automated version and security
updates on go.mod and GitHub Actions

.github/dependabot.yml

@@ -0,0 +1,12 @@
+version: 2
+updates:
+  - package-ecosystem: "gomod"
+    directory: "/"
+    # Check for updates once a day
+    schedule:
+      interval: "daily"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    # Check for updates once a week
+    schedule:
+      interval: "weekly"