Add VSCode IntelliSense support.

jsconfig.json

@@ -0,0 +1,13 @@
+{
+	// See https://go.microsoft.com/fwlink/?LinkId=759670
+	// for the documentation about the jsconfig.json format
+	"compilerOptions": {
+		"target": "es6",
+		"module": "commonjs",
+		"allowSyntheticDefaultImports": true
+	},
+	"exclude": [
+		"modules",
+		"node_modules"
+	]
+}