github: add labeler (pingcap#112)

Signed-off-by: hi-rustin <rustin.liu@gmail.com>

.github/labeler.yml

@@ -0,0 +1,14 @@
+sig/coprocessor:
+  - any: [ "sig/coprocessor/*","!sig/coprocessor/membership.json" ]
+
+sig/engine:
+  - any: [ "sig/engine/*","!sig/engine/membership.json" ]
+
+sig/raft:
+  - any: [ "sig/raft/*","!sig/raft/membership.json" ]
+
+sig/scheduling:
+  - any: [ "sig/scheduling/*","!sig/scheduling/membership.json" ]
+
+sig/transaction:
+  - any: [ "sig/transaction/*","!sig/transaction/membership.json" ]

.github/workflows/ labeler.yml

@@ -0,0 +1,12 @@
+name: "Pull Request Labeler"
+on:
+  - pull_request_target
+
+jobs:
+  triage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/labeler@main
+        with:
+          repo-token: "${{ secrets.GITHUB_TOKEN }}"
+          sync-labels: true