Fix formatting, change to markdown block for long

Fixed a couple issues with formatting.  Moved README-short to be a single line quote to emphasize that is it just a single line file and each character counts.  Moved README.md to be a fenced code block so that it is easier to compare to real readme examples.  This allows us to show the raw markdown whether on the website or through the raw file in the source tree.

Tested in `make docs` and all renders correctly.