style: format everything with prettier

.github/workflows/build.yml

@@ -0,0 +1,18 @@
+name: Code validation
+
+on: ["push"]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: NPM Install
+        run: npm ci
+        env:
+          CI: true
+
+      - name: Lint
+        run: npm run format:check

.prettierrc

@@ -0,0 +1,6 @@
+{
+	"plugins": ["@prettier/plugin-php"],
+	"useTabs": true,
+	"tabWidth": 2,
+	"printWidth": 120
+}