The cmRST implementation and the list of capabilities documented in the
cmake-developer.7 manual must be kept in sync. Add a note to each file
to reference the other.
Document how CMake uses reStructuredText to provide the help manuals.
Cover supported inline markup and directives, the CMake Domain in
Sphinx, and cross-reference syntax.
Add "Module Documentation" and "Find Modules" subsections. Add to
Modules/readme.txt a textual reference to the cmake-developer.7 manual
and, while at it, fix the wiki URL domain.
Convert the content moved from Modules/readme.txt to valid
reStructuredText markup. Mainly, convert the lists of variables to
definition lists, wrap long lines in paragraph text, and add literal
block markup and indentation.
Move all content from Modules/readme.txt except for the link to the
module maintainers wiki page into "Help/manual/cmake-developer.7.rst".
This produces some invalid reStructuredText markup to be fixed in a
future commit.
