Add bonus content to documentation

A new section titled "Bonus content" has been added to the documentation, providing in-depth information on various aspects of Django REST framework's Serializers. This includes hyperlinks to additional resources for types of serializers, serializer fields, relations, validators, routers, viewsets, and the Browsable API.

Author: lipemorais

docs/index.md

@@ -233,6 +233,32 @@ Until here we just looked at Django stuff. Now we will  dive into Django Rest Fr
 - 💻 Exercise: Continuation of the API project with instructor support.
 - 💡 Purpose: Completing the API project, reinforcing learning through practice.
 
+## Bonus content
+
+### Serializers deep dive
+
+#### Types
+1. [Serializer](https://www.django-rest-framework.org/api-guide/serializers/#serializers)
+2. [Model Serializer](https://www.django-rest-framework.org/api-guide/serializers/#modelserializer)
+3. [Hyperlinked Model Serializer](https://www.django-rest-framework.org/api-guide/serializers/#hyperlinkedmodelserializer)
+
+### Serializer fields
+1. [Boolean](https://www.django-rest-framework.org/api-guide/fields/#boolean-fields)
+2. [String](https://www.django-rest-framework.org/api-guide/fields/#string-fields)
+3. [Numeric](https://www.django-rest-framework.org/api-guide/fields/#numeric-fields)
+4. [Date and time](https://www.django-rest-framework.org/api-guide/fields/#date-and-time-fields)
+
+### Serializer relations
+
+
+### [Validators](https://www.django-rest-framework.org/api-guide/validators/)
+
+### [Routers](https://www.django-rest-framework.org/api-guide/routers/)
+
+### [ViewSets](https://www.django-rest-framework.org/api-guide/viewsets/)
+
+### [The Browsable API](https://www.django-rest-framework.org/topics/browsable-api/)
+
 ## Q&A and Wrap-Up
 
 - 🎬 Lecture: Recap of the day's lessons, addressing questions.