Add Dependabot configuration for package updates

Configure Dependabot for npm and GitHub Actions updates.

Author: coliff

.github/dependabot.yml

@@ -0,0 +1,25 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: "/"
+    schedule:
+      interval: monthly
+    versioning-strategy: increase
+    open-pull-requests-limit: 1
+    groups:
+      all-dependencies:
+        patterns:
+          - "*"
+        update-types:
+          - "minor"
+          - "patch"
+
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: monthly
+    groups:
+      github-actions:
+        patterns:
+          - "*"
+    open-pull-requests-limit: 1