Meson doesn't currently provide a very helpful message when trying to generate a coverage report with clang, and in fact just silently fails for 2 of the 3 reports. Ideally Meson would support coverage with llvm-cov, or provide a more helpful error message. Until then, it seems it would be helpful to at least put a warning in the documentation
This is a cosmetic change because github seems to interpret those
correctly. Nonetheless, it adds unnecessary noise and makes people
modifying the pages think it might be needed.
See syntax guide at https://guides.github.com/features/mastering-markdown/
This allows us to more easily have the documentation in sync with
the source code as people will have to document new features etc
right at the time where they implement it.