doc: fix broken URL to event loop guide

PR-URL: nodejs#11670
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/timers.md

@@ -163,7 +163,7 @@ added: v0.0.1
 Cancels a `Timeout` object created by [`setTimeout()`][].
 
 
-[the Node.js Event Loop]: https://github.com/nodejs/node/blob/master/doc/topics/event-loop-timers-and-nexttick.md
+[the Node.js Event Loop]: https://nodejs.org/en/docs/guides/event-loop-timers-and-nexttick
 [`TypeError`]: errors.html#errors_class_typeerror
 [`clearImmediate()`]: timers.html#timers_clearimmediate_immediate
 [`clearInterval()`]: timers.html#timers_clearinterval_timeout