Math notation

[ventaquil]

GitHub Markdown allows to display math expressions - read more here.

Unfortunately README.md on crates.io do not support it. It would be nice to add support it on crates.io too.

For example check my repository and crate:

• ventaquil/human-bytesize-procmacro
• crates.io/crates/human-bytesize-procmacro

I have two different READMEs due to show different badges but almost whole content is the same.