Add automerge github action (#142)

.github/workflows/automerge.yml

@@ -0,0 +1,51 @@
+name: Dependabot & Pre-Commit auto-merge
+on: pull_request
+
+jobs:
+  automerge-dependabot:
+    runs-on: ubuntu-latest
+    if: github.actor == 'dependabot[bot]'
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Dependabot metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@v2
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+
+      - name: Enable Auto-Approve for Dependabot PRs
+        if: steps.metadata.outputs.update-type == 'version-update:semver-minor' || steps.metadata.outputs.update-type == 'version-update:semver-patch'
+        run: gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}
+
+      - name: Enable Auto-Merge for Dependabot PRs
+        if: steps.metadata.outputs.update-type == 'version-update:semver-minor' || steps.metadata.outputs.update-type == 'version-update:semver-patch'
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}
+
+  automerge-pre-commit:
+    runs-on: ubuntu-latest
+    if: github.actor == 'pre-commit-ci[bot]'
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Enable Auto-Approve for Pre-Commit
+        if: github.head_ref == 'pre-commit-ci-update-config'
+        run: gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}
+
+      - name: Enable Auto-Merge for Pre-Commit
+        if: github.head_ref == 'pre-commit-ci-update-config'
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}