Update Dependabot config

.github/dependabot.yml

@@ -2,7 +2,18 @@
 version: 2
 
 updates:
-  - package-ecosystem: "github-actions"
+  - package-ecosystem: "docker"
     directory: "/"
     schedule:
       interval: "weekly"
+    groups:
+      docker-all:
+        patterns: ["*"]
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    groups:
+      github-actions-all:
+        patterns: ["*"]