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/doc.list.do

@@ -0,0 +1,3 @@
+ls redo*.md t/*.md >$3
+redo-always
+redo-stamp <$3