ci: deploy storybook to gh-pages

.github/workflows/pages.yml

@@ -0,0 +1,33 @@
+name: pages
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  deploy:
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@01aecccf739ca6ff86c0539fbc67a7a5007bbc81
+      - name: Setup Node
+        uses: actions/setup-node@44c9c187283081e4e88b54b0efad9e9d468165a4
+        with:
+          node-version: '12.x'
+      - name: Get yarn cache directory path
+        id: yarn-cache-dir-path
+        run: echo "::set-output name=dir::$(yarn cache dir)"
+      - name: Cache dependencies
+        uses: actions/cache@70655ec8323daeeaa7ef06d7c56e1b9191396cbe
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
+      - run: yarn install
+      - run: yarn build-storybook
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@1828d864aeb7ba79a37f40035aa6d0b7ff66254f
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./storybook-static