Update vectors.md

Feel silly because it's just one thing but it was bothering me that the documentation tells you what you're not going to learn now instead of linking to the item in question.  Am total noob pls assist, where is power button. :)

Author: rundrop1

src/doc/trpl/vectors.md

@@ -1,8 +1,7 @@
 % Vectors
 
 A *vector* is a dynamic or "growable" array, implemented as the standard
-library type [`Vec<T>`](../std/vec/) (we'll talk about what the `<T>` means
-later). Vectors always allocate their data on the heap. Vectors are to slices
+library type [`Vec<T>`](../std/vec/) (Where `<T>` is a [Generic](./generics.md) statement). Vectors always allocate their data on the heap. Vectors are to slices
 what `String` is to `&str`. You can create them with the `vec!` macro:
 
 ```{rust}