doc: fix grammar in worker_threads.md

Signed-off-by: hyemimi <hyemi7375@gmail.com>
PR-URL: #64913
Reviewed-By: Aviv Keller <me@aviv.sh>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ulises Gascón <ulisesgascongonzalez@gmail.com>

Author: hyemimi

doc/api/worker_threads.md

@@ -1829,8 +1829,8 @@ is done within the event loop. So the event loop utilization is
 immediately available once the worker's script begins execution.
 
 An `idle` time that does not increase does not indicate that the worker is
-stuck in bootstrap. The following examples shows how the worker's entire
-lifetime never accumulates any `idle` time, but is still be able to process
+stuck in bootstrap. The following example shows how the worker's entire
+lifetime never accumulates any `idle` time, but is still able to process
 messages.
 
 ```mjs