Fix incorrect usage of Process::pipe() (#10672)

Author: AhmedAlaa4611

processes.md

@@ -219,7 +219,7 @@ Laravel also allows you to assign string keys to each process within a pipeline
 $result = Process::pipe(function (Pipe $pipe) {
     $pipe->as('first')->command('cat example.txt');
     $pipe->as('second')->command('grep -i "laravel"');
-})->start(function (string $type, string $output, string $key) {
+}, function (string $type, string $output, string $key) {
     // ...
 });
 ```