Reformat README as markdown

tl;dr [I made your document pretty](https://github.com/Ichimonji10/i2spd/blob/master/README.md).

From the [official website](http://daringfireball.net/projects/markdown/):

> Markdown is a text-to-HTML conversion tool for web writers. Markdown allows you to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid XHTML (or HTML).
>
> Thus, “Markdown” is two things: (1) a plain text formatting syntax; and (2) a software tool, written in Perl, that converts the plain text formatting to HTML. See the [Syntax](http://daringfireball.net/projects/markdown/syntax) page for details pertaining to Markdown’s formatting syntax. You can try it out, right now, using the online [Dingus](http://daringfireball.net/projects/markdown/dingus).

Markdown is a lightweight markup language (document annotation system) in much the same vein as reStructuredText and Textile. It does not aim to compete with feature-rich markup languages such as HTML and XML, but instead aims to be human-readable and easy to edit by hand. It has gained very wide popularity -- _this very message_ is formatted as Markdown, and GitHub converts it to HTML on the fly.

Anyway, I've rewritten your README as markdown, fiddled with the wording in a few places for readability purposes, and wrapped text at 80 characters wide.