[BUGFIX] Quote identifier `colPos` in documentation example

The `colPos` identifier must be quoted - triggered by `{#colPos}`
in TypoScript - to make the database query work on database systems
that support case-sensitive identifiers (e.g. like PostgreSQL).

See
https://docs.typo3.org/c/typo3/cms-core/master/en-us/Changelog/8.7/Importa
nt-80506-DbalCompatibleFieldQuotingInTypoScript.html and
https://docs.typo3.org/m/typo3/reference-typoscript/master/en-us/Functions
/Select.html#quoting-of-fields

Releases: master, 10.4
Resolves: #93517
Change-Id: I3ae9b9d269371920570472890a92ba925a3e9822
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/67925


Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>