Update docs/book/v5/core-features/dependency-injection.md

Author: alexmerlin

docs/book/v5/core-features/dependency-injection.md

@@ -15,7 +15,7 @@ DotKernel API comes out of the box with
 [dot-dependency-injection](https://github.com/dotkernel/dot-dependency-injection) package, which provide all we need for
 injecting dependencies in any object you want.
 
-`dot-dependency-injection` determines the dependencies by looking at the `#[Inject]` attribute,
+`dot-dependency-injection` determines the dependencies by looking at the `#[Inject]` attribute, added to the constructor
 added to the constructor of a class. Dependencies are specified as separate parameters of the `#[Inject]` attribute.
 
 For our example we will inject a `UserService` and `config` dependencies in a `UseHandler`.