add github action

Author: kenpusney

.github/workflows/publish.yml

@@ -0,0 +1,23 @@
+name: Publish GitHub Pages
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  deploy:
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions/setup-node@v2.1.2
+      - run: yarn
+
+      - name: Build
+        run: npx vuepress build
+
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./.vuepress/dist