fixes typos

Author: shajanjp

doc/api/worker_threads.md

@@ -302,7 +302,7 @@ In particular, the significant differences to `JSON` are:
 - `value` may contain circular references.
 - `value` may contain instances of builtin JS types such as `RegExp`s,
   `BigInt`s, `Map`s, `Set`s, etc.
-- `value` may contained typed arrays, both using `ArrayBuffer`s
+- `value` may contain typed arrays, both using `ArrayBuffer`s
    and `SharedArrayBuffer`s.
 - `value` may contain [`WebAssembly.Module`][] instances.
 - `value` may not contain native (C++-backed) objects other than `MessagePort`s.