I don't feel like submitting a PR for it, but you have one syntax error and one suboptimal piece of syntax in the readme at the bottom:

The Windows section should read:

    Minecraft folder: %appdata%\minecraft
    Worlds folder: %appdata%\minecraft\saves\<world>

(observe the "closing" percent sign)

and the OSX one could read:

    Minecraft folder: $HOME/Library/Application Support/minecraft
    Worlds folder: $HOME/Library/Application Support/minecraft/saves/<world>

or, of course, using the same tilde syntax as in Linux.

Fixed! Thanks