fix typo in PeroformanceResourceTiming.requestStart (mdn#42724)

Author: Mimori256

files/en-us/web/api/performanceresourcetiming/requeststart/index.md

@@ -8,7 +8,7 @@ browser-compat: api.PerformanceResourceTiming.requestStart
 
 {{APIRef("Performance API")}}{{AvailableInWorkers}}
 
-The **`requestStart`** read-only property returns a {{domxref("DOMHighResTimeStamp","timestamp")}} of the time immediately before the browser starts requesting the resource from the server, cache, or local resource. If the transport connection fails and the browser retires the request, the value returned will be the start of the retry request.
+The **`requestStart`** read-only property returns a {{domxref("DOMHighResTimeStamp","timestamp")}} of the time immediately before the browser starts requesting the resource from the server, cache, or local resource. If the transport connection fails and the browser retries the request, the value returned will be the start of the retry request.
 
 There is no _end_ property for `requestStart`. To measure the request time, calculate {{domxref("PerformanceResourceTiming.responseStart", "responseStart")}} - `requestStart` (see the example below).