chore: create build action

.github/workflows/build.yml

@@ -0,0 +1,18 @@
+name: build
+on:
+  push:
+    branches-ignore: [master]
+jobs:
+  main:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - id: yarn_cache
+        run: echo "::set-output name=dir::$(yarn cache dir)"
+      - uses: actions/cache@v2
+        with:
+          path: ${{ steps.yarn_cache.outputs.dir }}
+          key: yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: yarn-
+      - run: yarn
+      - run: yarn build