Updated npm in auto build to v12

Added vscode tasks for launching frontend and backend in dev mode

.github/workflows/build.yml

@@ -15,7 +15,10 @@ jobs:
       - name: checkout code
         uses: actions/checkout@v2
       - name: setup node
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v2
+        with:
+          node-version: '12'
+          cache: 'npm'
       - name: install dependencies
         run: |
           npm install

.vscode/tasks.json

@@ -0,0 +1,25 @@
+{
+	"version": "2.0.0",
+	"tasks": [
+		{
+			"type": "npm",
+			"script": "start",
+			"problemMatcher": [],
+			"label": "Dev: start frontend",
+			"detail": "ng serve"
+		},
+		{
+			"label": "Dev: start backend",
+			"type": "shell",
+			"command": "set YTDL_MODE=debug && node app.js",
+			"options": {
+				"cwd": "./backend"
+			},
+			"presentation": {
+				"reveal": "always",
+				"panel": "new"
+			},
+			"problemMatcher": []
+		}
+	]
+}