The markdown docs are only generated by make when node is installed (use
`make doc`). If you don't have node installed you can generate them yourself. 
Unfortunately there's no real standard for markdown and all the tools work 
differently. pandoc is one that seems to work well.

To generate an html version of a doc do something like:
pandoc --from=markdown --to=html --number-sections -o build/doc/rust.html doc/rust.md && git web--browse build/doc/rust.html

The syntax for pandoc flavored markdown can be found at:
http://johnmacfarlane.net/pandoc/README.html#pandocs-markdown

A nice quick reference (for non-pandoc markdown) is at:
http://kramdown.rubyforge.org/quickref.html