Macro generate_kind

macro_rules! generate_kind {
    (
		// Kind trait name (e.g., Kind1).
		$KindN:ident,
		// Apply type alias name (e.g., Apply1).
		$ApplyN:ident,
		// Brand trait name (e.g., Brand1).
		$BrandN:ident,
		// String representation of the kind (e.g., "* -> *").
		$kind_str:literal,
		// List of generic type parameters (e.g., (A, B)).
		($($T:ident),+)
	) => { ... };
}

Generates boilerplate for HKTs of a specific arity.