task: update README.md (#168)

Author: carlosthe19916

README.md

@@ -4,10 +4,13 @@
 [![Project Chat](https://img.shields.io/badge/zulip-join_chat-brightgreen.svg?style=for-the-badge&logo=zulip)](https://projectopenubl.zulipchat.com/)
 [![Supported JVM Versions](https://img.shields.io/badge/JVM-11--17-brightgreen.svg?style=for-the-badge&logo=Java)](https://github.com/project-openubl/xsender/actions/runs/472762588/)
 
-| Artifact                  | Version                                                                                                                                                                            |
-|---------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| XSender                   | [![Maven Central](https://img.shields.io/maven-central/v/io.github.project-openubl/xsender)](https://search.maven.org/artifact/io.github.project-openubl/xsender/)                 |
-| XSender Quarkus extension | [![Maven Central](https://img.shields.io/maven-central/v/io.github.project-openubl/quarkus-xsender)](https://search.maven.org/artifact/io.github.project-openubl/quarkus-xsender/) |
+| Artifact                      | Version                                                                                                                                                                              |
+|-------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| XBuilder                      | [![Maven Central](https://img.shields.io/maven-central/v/io.github.project-openubl/xbuilder)](https://search.maven.org/artifact/io.github.project-openubl/xbuilder/)                 |
+| XBuilder Quarkus extension    | [![Maven Central](https://img.shields.io/maven-central/v/io.github.project-openubl/quarkus-xbuilder)](https://search.maven.org/artifact/io.github.project-openubl/quarkus-xbuilder/) |
+| XSender                       | [![Maven Central](https://img.shields.io/maven-central/v/io.github.project-openubl/xsender)](https://search.maven.org/artifact/io.github.project-openubl/xsender/)                   |
+| XSender Quarkus extension     | [![Maven Central](https://img.shields.io/maven-central/v/io.github.project-openubl/quarkus-xsender)](https://search.maven.org/artifact/io.github.project-openubl/quarkus-xsender/)   |
+| XSender Spring Boot extension | [![Maven Central](https://img.shields.io/maven-central/v/io.github.project-openubl/spring-boot-xsender)](https://search.maven.org/artifact/io.github.project-openubl/spring-boot-xsender/)   |
 
 # XBuilder
 
@@ -35,7 +38,7 @@ mvn clean test -Dxbuilder.snapshot.update
 Libreria para realizar envíos de comprobantes electrónicos a los servicios web de la SUNAT y/o OSCE de acuerdo a lo
 especificado por la SUNAT.
 
-## Getting started
+# Getting started
 
 - [Documentación](https://project-openubl.github.io)
 - [Discusiones](https://github.com/project-openubl/xsender/discussions)