Configure Dependabot for npm and GitHub Actions

Added npm and GitHub Actions package ecosystems for Dependabot updates with weekly schedule and cooldown settings.

Author: ocean

.github/dependabot.yml

@@ -0,0 +1,19 @@
+version: 2
+updates:
+  - package-ecosystem: "npm"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    cooldown:
+      default-days: 7
+    assignees:
+      - "ocean"
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    cooldown:
+      default-days: 7
+    assignees:
+      - "ocean"