chore: added 'Assign Reviewer' CI step

.github/workflows/assign-reviewer.yml

@@ -0,0 +1,13 @@
+name: 'Assign Reviewer'
+on:
+  pull_request:
+    types: [opened]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: uesteibar/reviewer-lottery@v1
+        with:
+          repo-token: ${{ secrets.GH_TOKEN }}