Macro readable::ryu

macro_rules! ryu {
    ($float:ident) => { ... };
}

Use ryu to format a float (without commas).

This takes a ryu::Float as input and outputs a &str.

If the feature flag ignore_nan_inf is enabled, this uses ryu::Buffer::format_finite which does not check for NaN or infinity.

Else, it uses ryu::Buffer::format, which does.