add vscode launch config and workspace settings (#2828)

.vscode/launch.json

@@ -0,0 +1,21 @@
+{
+  // Use IntelliSense to learn about possible attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Launch Unit Test",
+      "description": "launch test on current unit test file",
+      "program": "${workspaceFolder}/node_modules/mocha/bin/mocha",
+      "args": [
+        "--reporter=spec",
+        "--inspect-brk=9229",
+        "${file}"
+      ],
+      "port": 9229
+    },
+  ]
+}

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "editor.tabSize": 2
+}