added lighthouse ci github action

.github/workflows/lighthouse.yaml

@@ -0,0 +1,26 @@
+name: Lighthouse CI performance check
+on: [push, pull_request]
+
+jobs:
+  performance_check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node
+        uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Build website
+        run: npm run build --if-present
+
+      - name: Run Lighthouse against public directory
+        uses: treosh/lighthouse-ci-action@v3
+        with:
+          uploadArtifacts: true
+          temporaryPublicStorage: true
+          configPath: './lighthouserc.json'
+          runs: 3

lighthouserc.json

@@ -0,0 +1,19 @@
+{
+  "ci": {
+    "collect": {
+      "url": ["http://localhost/", "http://localhost/404/", "http://localhost/page-2"],
+      "staticDistDir": "./public"
+    },
+    "assert": {
+      "assertions": {
+        "categories:accessibility": ["error", { "minScore": 0.85 }],
+        "categories:best-practices": ["error", { "minScore": 0.8 }],
+        "categories:performance": ["error", { "minScore": 0.75 }],
+        "categories:seo": ["warn", { "minScore": 1 }],
+        "dom-size": ["warn", { "maxNumericValue": 1000 }],
+        "first-contentful-paint": ["error", { "maxNumericValue": 2500 }],
+        "interactive": ["error", { "maxNumericValue": 5000 }]
+      }
+    }
+  }
+}