ci(workflow): add 'npm' cache for actions/setup-node in .github/workflows

Author: oscard0m

.github/workflows/build.yml

@@ -6,10 +6,10 @@ on:
       - main
       - releases/*
     paths-ignore:
-      - '**.md'
+      - "**.md"
   pull_request:
     paths-ignore:
-      - '**.md'
+      - "**.md"
 
 jobs:
   build:
@@ -24,6 +24,7 @@ jobs:
         uses: actions/setup-node@v2
         with:
           node-version: 12.x
+          cache: npm
       - run: npm ci
       - run: npm run build
       - run: npm run format-check