minor cosmetic update

src/essentials/types/generics.md

@@ -49,7 +49,7 @@ fn main() {
 }
 ```
 
-** Generic Enums**: 
+**Generic Enums**: 
 
 Enums that can hold variants of different types specified at the time of instantiation.
 
@@ -66,4 +66,4 @@ fn main() {
     println!("Some number: {:?}", some_number);
     println!("Some string: {:?}", some_string);
 }
-```
+```