Replace Drone CI configuration with GitHub Actions workflow and update README badge

.gitea/workflows/ci.yml

@@ -0,0 +1,33 @@
+name: CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 'lts/*'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Run linter
+        run: npm run lint
+
+      - name: Run tests
+        run: npm run test
+
+      - name: Build project
+        run: npm run build