[DOCS] Clarify switch to `options.hideModules` user TSconfig option

While introducing the new module registration API,
the previously used page TSconfig options to hide
modules has been replaced by an extended user TSconfig
option. This change (page TSconfig -> user TSconfig)
is now clarified in the corresponding changelog.

Resolves: #103627
Releases: main, 12.4
Change-Id: Ic701cf0674c8ff1ed18273ad2629b2217947f7c9
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83852


Tested-by: Lina Wolf <112@linawolf.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Lina Wolf <112@linawolf.de>