Extend doc when using QtCreator IDE package taken from qt.io

[petricf]

Is your feature request related to a problem? Please describe.
The IDE package from qt.io adds start menu items for a command line session dependent on Qt version. This sets up the environment variables pointing to the Qt directories required.
But it does not set up the environment required to get the compiler paths. You have to start an other batch file "vcvarsall.bat amd64" (here located at: \Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat).

Describe the solution you'd like
Document this for the windows build even it is not a pure maplibre problem.
Example (here for Qt 6.6.3 and my visual studio installation):

• start "Qt 6.6.3 (MSVC 2019 64bit)"
• execute "\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" amd64
• execute cmake as documented at https://github.com/maplibre/maplibre-native-qt/blob/main/docs/Building.md

Describe alternatives you've considered
Load CMakeLists.txt as QtCreator project. Up to now didn't get it compiling inside QtCreator

Additional context