Registration fixes and improvements.

src/static_data/species_data/gender.rs

@@ -3,6 +3,7 @@
 /// Required for standard pokemon functions, but somewhat controversial nowadays. Consider adding a feature
 /// that allows for a more progressive gender system for those that want it?
 #[derive(Eq, PartialEq, Copy, Clone, Debug)]
+#[repr(u8)]
 pub enum Gender {
     /// The Pokemon has no gender.
     Genderless = 0,