add workflow for upload zip

.github/workflows/artifact.yml

@@ -0,0 +1,27 @@
+name: Upload artifact
+
+on: [push, pull_request]
+
+jobs:
+  doc:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python 3.7
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.7
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install --user -r tools/requirements.txt
+      - name: generate doc
+        run: |
+          cd tools &&
+          ./generate_document.py &&
+          ./generate_zip.py
+      - name: Upload zip
+        uses: actions/upload-artifact@v2
+        with:
+          name: ac-library
+          path: tools/ac-library.zip