Building Linux parallel parameter shell freezes

[Nickrader]

Documentation, https://github.com/cpp-sc2/cpp-sc2/blob/master/docs/building.md#linux-cmdline , shows building using parameter --parallel.

This can cause shell to lockup when building protobuf.
Building CXX object _deps/protobuf-build/CMakeFiles/libprotobuf.dir/src/google/protobuf/compiler/subprocess.cc.o

Workaround to pass 'n-1' threads your cpu supports to --parallel parameter.
E.g. cmake --build build --parallel -j 7 assuming your cpu supports 8 threads.

To Reproduce
Follow build steps using Linux, leaving '--parallel' as is.

Expected behavior
Finish compilation of project

Desktop (please complete the following information):

• OS / Distro: Ubuntu 23.10

I am assuming this would fall under documentation change? Or maybe fails elsewhere for others?

[alkurbatov]

Updated the documentation.