Add some reference DDD resources in english/spanish (#5471)

* Improve pages/markdown headings compatibility

* Add "Asombroso DDD" metalist

* Add "Domain Driven Design with PHP" playlist

"Domain Driven Design with PHP (spanish)" playlist
Carlos Buenosvinos Zamora @carlosbuenosvinos
https://www.youtube.com/playlist?list=PLfgj7DYkKH3DjmXTOxIMs-5fcOgDg_Dd2

* Add "Domain Driven Design with PHP" playlist

- Fix markdown syntax

"Domain Driven Design with PHP (spanish)" playlist
Carlos Buenosvinos Zamora @carlosbuenosvinos
https://www.youtube.com/playlist?list=PLfgj7DYkKH3DjmXTOxIMs-5fcOgDg_Dd2

* Add Codelytv "Domain-Driven Design"playlist

Domain-Driven Design (Diseño dirigido por Dominio) youtube playlist
Codely.tv
https://www.youtube.com/playlist?list=PLZVwXPbHD1KMsiA7ahRSbIwS3QMsQ0SbL

* Add CodelyTV screencasts

Codelytv screencasts
Codely.tv @codelytv
https://codely.tv/blog/screencasts

* Improve pages/markdown headings compatibility

* Add "Domain Driven Design Europe" conf screencast

Domain Driven Design Europe
https://2016.dddeurope.com/#videos
https://2017.dddeurope.com/#videos
https://dddeurope.com/2018/
https://dddeurope.com/2019/
https://dddeurope.com/2020/
https://dddeurope.com/2021/

* Add DDD Europe's First 15 years book

Domain-Driven Design: The First 15 Years. Essays from the DDD community
https://leanpub.com/ddd_first_15_years/
https://dddeurope.com/15years/

books/free-programming-books-es.md

@@ -54,6 +54,7 @@
 
 * [Aprender Python](https://wiki.python.org.ar/aprendiendopython/) - Python Argentina
 * [Apuntes Completos de Desarrollo Web](http://jorgesanchez.net) - Jorge Sánchez
+* [Asombroso DDD: Una lista curada de recursos sobre Domain Driven Design](https://github.com/ddd-espanol/asombroso-ddd)
 * [Desarrollo de Aplicaciones Web - Temario Completo](https://github.com/statickidz/TemarioDAW#temario-daw) - José Luis Comesaña (Github)
 * [Desarrollo de Aplicaciones Web y Sistemas Microinformáticos y Redes](https://javiergarciaescobedo.es) - Javier García Escobedo
 * [Gitbook - Libros útiles en español](https://github.com/DpdC/gitbook-biblioteca-impresionante-en-espanol#gitbook---biblioteca-de-libros-en-español--) (Github)
@@ -128,7 +129,7 @@
 * [Introducción a la programación con C](http://repositori.uji.es/xmlui/bitstream/handle/10234/24306/s29.pdf) (PDF) (descarga directa)
 
 
-<h3 id="cpp">C++</h3>
+### <a name="cpp"></a>C++
 
 * [Aprenda C++ avanzado como si estuviera en primero](https://web.archive.org/web/20100701020037/http://www.tecnun.es/asignaturas/Informat1/AyudaInf/aprendainf/cpp/avanzado/cppavan.pdf) (PDF)
 * [Aprenda C++ básico como si estuviera en primero](https://web.archive.org/web/20100701020025/http://www.tecnun.es/asignaturas/Informat1/AyudaInf/aprendainf/cpp/basico/cppbasico.pdf) (PDF)
@@ -284,6 +285,7 @@
 
 ### PHP
 
+* [Domain Driven Design with PHP (Diseño guiado por Dominio con PHP)](https://www.youtube.com/playlist?list=PLfgj7DYkKH3DjmXTOxIMs-5fcOgDg_Dd2) - Carlos Buenosvinos Zamora (Youtube playlist)
 * [Manual de estudio introductorio al lenguaje PHP procedural](https://web.archive.org/web/20140209203630/http://www.cursosdeprogramacionadistancia.com/static/pdf/material-sin-personalizar-php.pdf) (PDF)
 * [PHP y Programación orientada a objetos](https://styde.net/php-y-programacion-orientada-a-objetos/) (HTML)
 * [POO y MVC en PHP](http://www.bubok.es/libros/205199/POO-y-MVC-en-PHP) (Bubok)

books/free-programming-books.md

@@ -880,6 +880,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Data-Oriented Design](http://www.dataorienteddesign.com/dodmain/dodmain.html)
 * [Developing Reactive Microservices](https://info.lightbend.com/COLL-20XX-Developing-Reactive-Microservices_Landing-Page.html) (email address *requested*, not required)
 * [Domain Driven Design Quickly](http://www.infoq.com/minibooks/domain-driven-design-quickly)
+* [Domain-Driven Design: The First 15 Years. Essays from the DDD community](https://dddeurope.com/15years/) - Domain-Driven Design Europe ([HTML, PDF, ePub](https://leanpub.com/ddd_first_15_years/)) *(Leanpub account or valid email requested)*
 * [DSL Engineering: Designing, Implementing and Using Domain-Specific Languages](http://dslbook.org) - Markus Voelter
 * [Exploring CQRS and Event Sourcing](https://docs.microsoft.com/en-us/previous-versions/msp-n-p/jj554200(v=pandp.10)) - Dominic Betts, Julián Domínguez, Grigori Melnik, Mani Subramanian, Fernando Simonazzi ([EPUB, PDF](http://www.microsoft.com/en-us/download/details.aspx?id=34774) - [code samples](http://go.microsoft.com/fwlink/p/?linkid=258571))
 * [Guide to the Software Engineering Body of Knowledge](https://www.computer.org/education/bodies-of-knowledge/software-engineering/v3) (email adddress *requested*)