VSCode debug task for debugging main process

Summary: Just a small task to make debugging of the main process easier

Reviewed By: jknoxville

Differential Revision: D19792592

fbshipit-source-id: 9d1060dbb58a01615230bff2361144cfc88e41b7

.vscode/launch.json

@@ -9,6 +9,12 @@
       "webRoot": "/",
       "url": "http://localhost:3000/index.dev.html"
     },
+    {
+      "name": "Attach to Running Main",
+      "type": "node",
+      "request": "attach",
+      "port": 9229
+    },
     {
       "type": "node",
       "request": "launch",