Add vscode config to prefer node_modules TS ver.

This config (optionally) hints to the Typescript extension that the project's
Typescript version (which is often bleeding edge/"RC") should be used. As this
is a HelloWorld mod project, my hope is that it might be useful for
mitigating yet another confusing roadblock for would be modders in the event
of some TS incompatibility.

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "typescript.tsdk": "node_modules/typescript/lib"
+}