[DOCS] Remove unused files in Documentation folder

* .gitignore files contain files that are not
  created during rendering
* .editorconfig conatains old styling, there is a
  main .editorconfig with the containing the correct
  styling

Resolves: #103352
Releases: main, 12.4, 11.5
Change-Id: Ic3189d5f10b8e6f8aa8903cd0924a4a4b4fab191
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83392


Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Reviewed-by: Lina Wolf <112@linawolf.de>
Tested-by: Lina Wolf <112@linawolf.de>
Tested-by: Garvin Hicking <gh@faktor-e.de>