add comment to default config, fixes #4291

extensions/typescript/src/utils/projectStatus.ts

@@ -181,6 +181,8 @@ function computeLargeRoots(configFileName:string, fileNames: string[]): string[]
 }
 
 const defaultConfig = `{
+	// See http://go.microsoft.com/fwlink/?LinkId=733559
+	// for the documentation about the jsconfig.json format
 	"compilerOptions": {
 		"module": "commonjs"
 	},