[Rust] Fixed codegen documentation for Tables (#5227)

tests/monster_test_generated.rs

@@ -920,10 +920,10 @@ impl<'a: 'b, 'b> ReferrableBuilder<'a, 'b> {
   }
 }
 
-/// an example documentation comment: monster object
 pub enum MonsterOffset {}
 #[derive(Copy, Clone, Debug, PartialEq)]
 
+/// an example documentation comment: monster object
 pub struct Monster<'a> {
   pub _tab: flatbuffers::Table<'a>,
 }