This avoids a mkdocs bug where mkdocs will (rarely) see redo temp files
in its directory list, but they're gone by the time it tries to open
them, so it aborts with an exception.
No content yet other than man pages. To make the man pages render
nicely in mkdocs, I removed the static %-headers and put the code for
them into default.md.tmp.do instead. That way, the raw input redo-*.md
files will look right in mkdocs.
