This is because when generating man page, if a word starting '.' is
put in the beginning of the line, it will be treated as macro. This
sounds like docutils bug, but it will not be fixed soon, so we do this
as a workaround.
The source files for manual pages are placed under doc/manual-src.
The built manual pages are placed under doc/manual.
When installed, manual pages are placed under $(docdir)/manual/.