Closes #1320

There are a few issues with that guideline:
- Using program-serial is not guaranteed to work as expected after a module load mpi, e.g. due to the use of LD_LIBRARY_PATH
- This creates a burden on the upstream project to support this packaging decisions. E.g. a Fortran gem that I was shown: https://github.com/cp2k/cp2k/blob/39fc2feded38fb50f7b1c74dba66523010dcedba/src/start/cp2k.F#L155-L159, where the suffix of the executable is used in the execution of the code
- It is a non-standard implementation which can affect other tools that try to find the executable through PATH

I also wanted to add the trick with %global _vpath_builddir %{_vendor}-%{_target_os}-build${MPI_SUFFIX:-_serial}, but I need to look at %configure macro to figure out how to make that work. I know for CMake, we can basically use the approach here.

While at it, I have also refactored the document a bit. I am not familiar with ASCIIIDOC, so I am not sure what is a proper way to write these.