Readme add: cmake -T cuda=

[ptheywood]

For Windows users with mutliple CUDA installations, it might be useful to add the use of -T cuda=<version> to our windows cmake configuration readme, to select non-default versions of CUDA.

I.e. with CUDA 12.4, 12.5 and 12.6 installed on windows, with 12.6 being found by deafault, you can select an older toolkit using:

cmake -S . -B build -T cuda=12.5  

(I.e. I have to look this occasioanlly and searching often brings up unrelated stack overflow posts rather than the answer)

[Robadob]

It's noted in the userguide

https://docs.flamegpu.com/quickstart/index.html#compiling-your-project