Updates to C++ and Chem Kinetics page

[yandthj]

• remove ansys version number from load commands on chemical kinetics page
• On C++ page change name to stream instead of matrix multiplication, based on Tim K's comment on PR More C++ examples. CUDA and MPI+CUDA. Draft 0, review required #793: "This is stream not matrix Multiplication. Stream is fine. I think it is actually more important since matrix multiplication would more likely be done with a library."
• Add instructions to run GUI apps on compute nodes to main FastX page