[CI] add github action with misspellcheck

just for pull requests

.github/workflows/autoreview.yml

@@ -0,0 +1,12 @@
+name: autoreview
+on: [pull_request]
+
+jobs:
+  misspellcheck:
+    runs-on: ubuntu-20.04
+    steps:
+    - uses: actions/checkout@v2
+    - name: Run misspell with reviewdog
+      uses: reviewdog/action-misspell@v1
+      #with:
+      #  pattern: "*.md"