There were erroneous backslashes for non-dashed options (e.g \fB\option instead
of \fBoption) and missing linebreaks. Both are fixed now. Kudos got to linitian
for noticing the regressions.
The directory doc already exists and there does not seem a need to
introduces docs as an additional source of documentation.
With this change the doc layout is similar to opm-common and
opm-simulators.
This means that it becomes harder to move this directory around, but
that gain is relatively small anyway. It is however necessary to do
this if we are not going to do a recursive build style.