Add Vitest coverage reporting to Woodpecker CI

.woodpecker.yml

@@ -0,0 +1,12 @@
+steps:
+  verify:
+    image: node:20
+    commands:
+      - npm ci
+      - npm run test:coverage
+      - npm run build
+
+when:
+  event:
+    - push
+    - pull_request