The header levels have been switched to correspond more with the Sphinx
suggested standards and the troubleshooting section has been
restructured to make it easier to find solutions. Minor markup changes
and other changes are also included in this commit.
There is no need in regenerating font cache in *all* directories.
Make documentation suggest to regenerate just `~/.fonts` cache
which actually changed.
Kim Silkebækken
ZyX-I