doc: Add youtube badge to README

Author: fabapp2

README.adoc

@@ -4,6 +4,7 @@
 image:https://img.shields.io/github/license/spring-projects-experimental/spring-boot-migrator[GitHub]
 image:https://img.shields.io/github/v/release/spring-projects-experimental/spring-boot-migrator[GitHub release (latest by date)]
 image:https://img.shields.io/github/downloads/spring-projects-experimental/spring-boot-migrator/0.13.0/total[GitHub release (latest by date)]
+image:https://img.shields.io/youtube/channel/views/UC6NuSiwpvI32YTcdIflObPQ?logo=youtube&style=flat-square[YouTube Channel Views]
 
 image:https://img.shields.io/badge/Join-Slack-green?logo=slack&color=007EC6&style=for-the-badge[link="https://join.slack.com/t/springbootmigrator/shared_invite/zt-1k6yxfi3b-MEQ_MM67qXufWtc~Tw6y9w"]
 image:https://img.shields.io/github/discussions/spring-projects-experimental/spring-boot-migrator?label=GitHub%20discussions&logo=GitHUb&style=for-the-badge[GitHub Discussions]