Derive Alias

Provides a way to alias mutliple derives as one: ```rust use derivealias::derivealias;

// Generates a macro (derive_cmp) that will attach the listed derives to a given item derivealias! { derivecmp => #[derive(Eq, PartialEq, Ord, PartialOrd)] }

// Attach the derives to Foo derive_cmp! { struct Foo; } ```

You can create multiple aliases at a time: ```rust use derivealias::derivealias;

derivealias! { derivecmp => #[derive(Eq, PartialEq, Ord, PartialOrd)], derive_other => #[derive(Copy, Clone)] }

derivecmp! { struct Foo; } deriveother! { struct Bar; } ```