Building OpenFOAM on different computing systems

[colemanjs]

There are currently two requests regarding optional builds of OpenFOAM for different computing environments:

Issue #1 : Provides guidance on building OpenFOAM on Frontier using clang compilers and MPICH.
PR #24 : Offers build scripts to reduce OpenFOAM-10 build time by compiling only the libraries required for AdditiveFOAM.

This discussion will serve as a centralized place for addressing OpenFOAM-specific build issues, keeping them separate from the main AdditiveFOAM branch, to better support users facing similar challenges.