Update README to be more GitHub-friendly

Uses more of the regular and [GitHub Flavored Markdown](https://help.github.com/articles/github-flavored-markdown/) to look more structured on GitHub.

You can see [rendered page with these changes applied](https://github.com/cust0dian/tron/blob/d5ecdf9e9f06eea9c5bfb5c9bec4478d7b0c9725/README.md) in my fork.