feat(books): `CI/CD for Monorepos` by SemaphoreCI (#6583)

* feat(books): `CI/CD for Monorepos` by SemaphoreCI

CI/CD for Monorepos: Effectively building, testing, and deploying code with monorepos

Author: Pablo Tomas Fernandez Zavalia,
Editor:   Marko Anastasov, 
Publisher: SemaphoreCI
Format: PDF, EPUB, Kindle, Markdown, TeX
Year: 2021

Sources Repo: https://github.com/semaphoreci/book-monorepo-cicd
Download Page: https://semaphoreci.com/resources/monorepo-cicd
Back PDF: https://wpblog.semaphoreci.com/wp-content/uploads/2021/08/CICD_for_Monorepos.pdf

* fix: Apply PR review removing multiformat. One link is enough

books/free-programming-books-subjects.md

@@ -223,6 +223,7 @@ Books that cover a specific programming language can be found in the  [BY PROGRA
 
 ### Containers
 
+* [CI/CD for Monorepos: Effectively building, testing, and deploying code with monorepos](https://github.com/semaphoreci/book-monorepo-cicd) - Pablo Tomas Fernandez Zavalia, Marko Anastasov, SemaphoreCI (PDF, EPUB, Kindle)
 * [CI/CD with Docker and Kubernetes Book](https://github.com/semaphoreci/book-cicd-docker-kubernetes) - Marko Anastasov, Jérôme Petazzoni, Pablo Tom F. Zavalia, SemaphoreCI (PDF, EPUB, Kindle)
 * [Docker Jumpstart](http://odewahn.github.io/docker-jumpstart/) - Andrew Odewahn
 * [Kubernetes Deployment & Security Patterns](https://resources.linuxfoundation.org/LF+Projects/CNCF/TheNewStack_Book2_KubernetesDeploymentAndSecurityPatterns.pdf) - Alex Williams (PDF)