Generate a basic documentation website with the mkdocs toolkit.

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.

Documentation/clean.do

@@ -1 +1 @@
-rm -f *~ .*~ *.1 t/*.1 md-to-man *.tmp t/*.tmp *.html */*.html
+rm -f *~ .*~ *.1 t/*.1 md-to-man *.tmp t/*.tmp *.html */*.html *.list