[TASK] Use @import syntax in TypoScript example

The TypoScript which is created by the Install Tool should use the new
@import syntax.

Resolves: #88623
Releases: master, 9.5
Change-Id: I661cbe7bbc659c6ea804f4b131aa49fc7abca92a
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61244


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Josef Glatz <josefglatz@gmail.com>
Tested-by: Jörg Bösche <typo3@joergboesche.de>
Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: Steffen Frese <steffenf14@gmail.com>
Tested-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Josef Glatz <josefglatz@gmail.com>
Reviewed-by: Jörg Bösche <typo3@joergboesche.de>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Steffen Frese <steffenf14@gmail.com>
Reviewed-by: Dieter Porth <d.porth@neusta.de>
Reviewed-by: Julian Geils <j_geils@web.de>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>