docs(generics): add bounds help

add help for bounds provided by the rust by example book

exercises/generics/README.md

@@ -4,4 +4,5 @@ In this section you'll learn about saving yourself many lines of code with gener
 
 ### Book Sections
 
-- [Generic Data Types](https://doc.rust-lang.org/stable/book/ch10-01-syntax.html)
+- [Generic Data Types](https://doc.rust-lang.org/stable/book/ch10-01-syntax.html)
+- [Bounds](https://doc.rust-lang.org/rust-by-example/generics/bounds.html)