add auto assign reviewer github action (#2854)

* test: add auto assign reviewer github action

* TomShawn -> yikeke

.github/assign-by-files.yml

@@ -0,0 +1,38 @@
+---
+# you can use glob pattern
+
+# You can set multiple reviewers
+# '.github/':
+#   - yikeke
+#   - ran-huang
+
+# 'tiflash/':
+#   - zanmato1984
+#   - kissmydb
+#   - yikeke
+
+# 'tiup/':
+#   - lonng
+#   - lucklove
+#   - kissmydb
+#   - yikeke
+
+# 'sql-statements/':
+#   - bb7133
+
+# 'releases/':
+#   - scsldb
+
+# 'dashboard/':
+#   - breeswish
+
+# 'config-templates/':
+#   - kissmydb
+
+# 'ticdc/':
+#   - WangXiangUSTC
+
+# Changing all md files should request a language review in case of format failures.
+# TomShawn is the repo administrator.
+'*.*':
+  - yikeke

.github/workflows/auto-assign.yml

@@ -0,0 +1,15 @@
+name: "Auto Assign"
+on:
+  pull_request:
+    branches:
+      - master
+    types: [opened]
+
+jobs:
+  assign_reviewer:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: shufo/auto-assign-reviewer-by-files@v1.0.0
+      with:
+        config: '.github/assign-by-files.yml'
+        token: ${{ secrets.GITHUB_TOKEN }}