Add mergeable bot configuration

.github/mergeable.yml

@@ -0,0 +1,19 @@
+# This file (`.github/mergeable.yml`) is the configuration of the mergeable bot:
+# https://github.com/apps/mergeable
+
+version: 2
+mergeable:
+  - when: pull_request.*, pull_request_review.*
+    validate:
+      - do: commit
+        message:
+          regex: ^.*(@antgroup\.com|@alibaba-inc\.com|@intel\.com)$
+          message: Check if the author emails belong to Ant Group or its partners
+          message_type: author_email
+          skip_merge: false # If true, will skip commit with message that includes 'Merge'
+          oldest_only: false
+          newest_only: false
+          single_commit_only: false # If true, will only process this validator if there is one commit
+    pass:
+      - do: checks
+        status: 'success'