Add timestamp to debug logging (#994)

* add timestamp

* cra

* fix linting

* re-add square brackets

Author: sylc

src/index.ts

@@ -38,7 +38,9 @@ function yn (value: string | undefined) {
  * Debugging `ts-node`.
  */
 const shouldDebug = yn(process.env.TS_NODE_DEBUG)
-const debug = shouldDebug ? console.log.bind(console, 'ts-node') : () => undefined
+const debug = shouldDebug ?
+  (...args: any) => console.log(`[ts-node ${new Date().toISOString()}]`, ...args)
+  : () => undefined
 const debugFn = shouldDebug ?
   <T, U> (key: string, fn: (arg: T) => U) => {
     let i = 0