README -> README.md
As documentation maintainer, I've decided we will move the README to markdown format and use the '.md' extension.
This change will take effect after the release of 2.1.0
I've outlined my reasoning:
- RDoc now has a built-in markdown parser, writing markdown is much easier
- This change will encourage contributors who are able to read and write markdown
- Github is a large source of new contributors, this change will improve README formatting on github
I will need assistance converting the existing Japanese README.ja to markdown format, any help here is appreciated! Please raise your hand if you'd like to help with the conversion.