doc: Add native C++ build instructions
cpp: Remove README
doc: Add C++ conversion text
doc: Fix title capitalisation
doc: cpp: Reword RedHat gtest paragraph
doc: cpp: Reword parallelisation
doc: cpp-conversion: Corrections
doc: cpp-conversion: Spelling changes
cpp: cpp-conversion: Use "cannot" rather than "can not"
Merge pull request #995 from rleigh-dundee/cpp-docs

C++ sphinx documentation