build: improved build scripts

package.json

@@ -5,8 +5,11 @@
   "main": "ass.js",
   "scripts": {
     "dev": "npm run build && npm start",
+    "build": "rm -dr dist/ & npm run build:backend && npm run build:frontend",
+    "build:backend": "tsc -p backend/",
+    "build:frontend": "tsc -p frontend/",
     "dev-win": "npm run build-skip-options && npm run start",
-    "build": "NODE_OPTIONS=\"--max-old-space-size=1024\" tsc",
+    "build-old": "NODE_OPTIONS=\"--max-old-space-size=1024\" tsc",
     "build-skip-options": "tsc",
     "start": "node dist/app.js",
     "setup": "node dist/setup.js",