ci: create dependabot config for Docker ecosystem

.github/dependabot.yml

@@ -0,0 +1,11 @@
+version: 2
+updates:
+
+  # Maintain dependencies for Docker
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    labels:
+      - "area/chore"
+      - "area/dockerfile"