Add pascalgn/automerge-action (#624)

Author: nakamura-to

.github/pr-labeler.yml

@@ -1,3 +1,4 @@
+automerge: ['chore/*', 'ci/*', 'docs/*', 'fix/*', 'refactor/*', 'test/*']
 chore: chore/*
 ci: ci/*
 dependencies: dependencies/*

.github/workflows/automerge.yml

@@ -0,0 +1,34 @@
+name: automerge
+
+on:
+  pull_request:
+    types:
+      - labeled
+      - unlabeled
+      - synchronize
+      - opened
+      - edited
+      - ready_for_review
+      - reopened
+      - unlocked
+  pull_request_review:
+    types:
+      - submitted
+  check_suite:
+    types:
+      - completed
+  status: {}
+
+env:
+  MERGE_METHOD: "squash"
+  MERGE_FORKS: "false"
+  UPDATE_METHOD: "rebase"
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    steps:
+      - name: automerge
+        uses: pascalgn/[email protected]
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}