chore: add Dependabot

Author: flaksp

.github/dependabot.yaml

@@ -0,0 +1,10 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: /
+    schedule:
+      interval: monthly
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: monthly

.github/workflows/dependabot.yml

@@ -0,0 +1,16 @@
+name: Dependabot
+
+on: pull_request_target
+
+jobs:
+  auto_approve_pr:
+    name: Auto-approve PR
+    runs-on: ubuntu-latest
+    if: github.actor == 'dependabot[bot]'
+
+    steps:
+      - name: Approve a pull request
+        run: gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GITHUB_TOKEN: ${{ github.token }}