Fix old docs references to $request

docs/create.md

@@ -8,7 +8,7 @@ Optionally pass a closure that returns a boolean value.
 $type->creatable();
 
 $type->creatable(function (Context $context) {
-    return $request->getAttribute('user')->isAdmin();
+    return $context->getRequest()->getAttribute('user')->isAdmin();
 });
 ```
 

docs/delete.md

@@ -8,7 +8,7 @@ Optionally pass a closure that returns a boolean value.
 $type->deletable();
 
 $type->deletable(function (Context $context) {
-    return $request->getAttribute('user')->isAdmin();
+    return $context->getRequest()->getAttribute('user')->isAdmin();
 });
 ```
 

docs/list.md

@@ -8,7 +8,7 @@ If you want to restrict the ability to list a resource type, use the `listable`
 $type->notListable();
 
 $type->listable(function (Context $context) {
-    return $request->getAttribute('user')->isAdmin();
+    return $context->getRequest()->getAttribute('user')->isAdmin();
 });
 ```
 

docs/update.md

@@ -8,7 +8,7 @@ Optionally pass a closure that returns a boolean value.
 $type->updatable();
 
 $type->updatable(function (Context $context) {
-    return $request->getAttribute('user')->isAdmin();
+    return $context->getRequest()->getAttribute('user')->isAdmin();
 });
 ```
 

docs/visibility.md

@@ -9,7 +9,7 @@ For example, the following schema will make an email attribute that only appears
 ```php
 $type->attribute('email')
     ->visible(function ($model, Context $context) {
-        return $model->id === $request->getAttribute('userId');
+        return $model->id === $context->getRequest()->getAttribute('userId');
     });
 ```