document custom directives

docs/master/custom-directives/field-directives.md

@@ -84,7 +84,7 @@ directive can be used to manipulate the schema AST.
 This directive type is implemented as an abstract class rather than a pure interface and allows
 you to define complex validation rules for a field with ease.
 
-[Read more about it in the Validation section](../security/validation.md#validate-fields).
+[Read more about it in the Validation section](../security/validation.md#validator-for-fields).
 
 ## ComplexityResolverDirective
 

docs/master/custom-directives/getting-started.md

@@ -1,13 +1,13 @@
 # Implementing Your Own Directives
 
 As you grow your GraphQL schema, you may find the need for more specialized functionality.
-Learn how you can abstract logic in a composable and reusable manner by using custom directives.
-
-Directives are implemented as PHP classes, each directive available
-in the schema corresponds to a single class.
+You can abstract logic in a composable and reusable manner by using custom directives.
 
 ## Naming Convention
 
+Directives are implemented as PHP classes.
+Each directive available in the schema corresponds to a single class.
+
 Directive names themselves are typically defined in **camelCase**.
 The class name of a directive must follow the following pattern:
 
@@ -51,12 +51,11 @@ GRAPHQL;
 ## Directive Interfaces
 
 At this point, the directive does not do anything.
-Depending on what your directive should do, you can pick one or more of the provided
-directive interfaces to add functionality. They serve as the point of contact to Lighthouse.
+Depending on what your directive should do, you can pick one or more of the provided directive interfaces to add functionality.
+They serve as the point of contact to Lighthouse.
 
 In this case, our directive needs to run after the actual resolver.
-Just like [Laravel Middleware](https://laravel.com/docs/middleware),
-we can wrap around it by using the `FieldMiddleware` directive.
+Just like [Laravel Middleware](https://laravel.com/docs/middleware), we can wrap around it by using the `FieldMiddleware` directive.
 
 ```php
 namespace App\GraphQL\Directives;
@@ -87,6 +86,9 @@ final class UpperCaseDirective extends BaseDirective implements FieldMiddleware
 }
 ```
 
+Given there are a lot of use cases for custom directives, the documentation does not provide examples for most interfaces.
+It is advised to look at the Lighthouse source code to find directives that implement certain interfaces to learn more.
+
 ## Register Directives
 
 Now that we defined and implemented the directive, how can Lighthouse find it?