minor #13027 Fix example with iterable (peterjaap)

This PR was submitted for the 5.0 branch but it was squashed and merged into the 4.4 branch instead (closes #13027). Discussion ---------- Fix example with iterable The old example throws this error; `PHP Fatal error: Uncaught TypeError: Argument 1 passed to Symfony\Component\Console\Helper\ProgressBar::iterate() must be iterable, object given` <!-- If your pull request fixes a BUG, use the oldest maintained branch that contains the bug (see https://symfony.com/roadmap for the list of maintained branches). If your pull request documents a NEW FEATURE, use the same Symfony branch where the feature was introduced (and `master` for features of unreleased versions). --> Commits ------- 36b6e43 Fix example with iterable

Author: OskarStark

components/console/helpers/progressbar.rst

@@ -110,11 +110,17 @@ which starts, advances and finishes the progress bar automatically::
 
  $progressBar = new ProgressBar($output);
 
- // $iterable can be for example an array ([1, 2, 3, ...]) or a generator
- // $iterable = function () { yield 1; yield 2; ... };
+ // $iterable can be for example an array ([1, 2, 3, ...])
+ $iterable = [1, 2];
  foreach ($progressBar->iterate($iterable) as $value) {
  // ... do some work
  }
+ 
+ // or a generator
+ function iterable() { yield 1; yield 2; ... };
+ foreach ($progressBar->iterate(iterable()) as $value) {
+ // ... do some work
+ }
 
 If ``$iterable = [1, 2]``, the previous code will output the following: