Add performance assertions in LH

Author: luisherranz

.github/workflows/lighthouse.yml

@@ -41,6 +41,7 @@ jobs:
         with:
           runs: 3
           temporaryPublicStorage: true
+          configPath: ./.github/workflows/lighthouserc.json
           urls: |
             https://mars-theme-frontity.worona.now.sh/
             https://mars-theme-frontity.worona.now.sh/2016/the-beauties-of-gullfoss/

.github/workflows/lighthouserc.json

@@ -0,0 +1,8 @@
+{
+  "assertions": {
+    "categories:performance": ["error", { "minScore": 0.99 }],
+    "categories:accessibility": ["error", { "minScore": 1 }],
+    "categories:best-practices": ["error", { "minScore": 1 }],
+    "categories:seo": ["error", { "minScore": 0.97 }]
+  }
+}