[handbook] Bump the required CMake version to 3.14. (!3476) · Merge requests · dumux-repositories / dumux · GitLab

What this MR does / why does DuMux need it:

Bump the required version of CMake to 3.14 in the handbook

does the new code follow the style guide?
do the test pipelines pass? (see guide on how to run pipelines for a merge request)

Edited Mar 23, 2023 by Ivan Buntic