build(gh): enable the dependabot

.github/dependabot.yml

@@ -0,0 +1,26 @@
+version: 2
+updates:
+  - package-ecosystem: "bundler"
+    directory: "/"
+    versioning-strategy: increase
+    groups:
+      bundler:
+        dependency-type: "production"
+    schedule:
+      interval: "weekly"
+  - package-ecosystem: "npm"
+    directory: "/"
+    versioning-strategy: increase
+    groups:
+      npm:
+        dependency-type: "development"
+    schedule:
+      interval: "weekly"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    groups:
+      gh-actions:
+        update-types:
+          - "major"
+    schedule:
+      interval: "weekly"