[DOCS] Replace reference to outdated "EditModule" in EXT:adminpanel

The module "EditModule" was removed with #87498, but the
documentation reference remained. Instead of using this module
as an example, instead "CacheModule" is referenced, since it
addresses similar demonstration purposes.

Backports are needed for proper documentation rendering.

Resolves: #104802
Related: #87498
Releases: main, 12.4, 11.5
Change-Id: Iab25eec9aec9765f1c71f439c00ca34975d7e8a1
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/85858


Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: Benni Mack <benni@typo3.org>

typo3/sysext/adminpanel/Documentation/Extending/Index.rst

@@ -145,5 +145,5 @@ Admin Panel extension. Short ones for a quick look are:
 *  `adminpanel/Classes/Modules/Info/PhpInformation.php` (Submodule)
 *  `adminpanel/Classes/Modules/InfoModule.php` (Main module, serves as
    submodule wrapper only)
-*  `adminpanel/Classes/Modules/EditModule.php` (Main module, custom rendering
+*  `adminpanel/Classes/Modules/CacheModule.php` (Main module, custom rendering
    settings)