[TASK] Add examples to AjaxRequest code

Resolves: #93518
Releases: master, 10.4
Change-Id: I9a745fc608b1f1ce24af8005910ce776cd00a163
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/67931


Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Richard Haeser <richard@richardhaeser.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Richard Haeser <richard@richardhaeser.com>