Add domain driven design to the course

[pintergreg]

• https://www.nareshbhatia.dev/articles/domain-driven-design
• https://github.com/ddd-crew
• https://github.com/ddd-crew/ddd-starter-modelling-process?tab=readme-ov-file
• https://dev.to/ruben_alapont/domain-driven-design-ddd-paradigm-a-comprehensive-guide-4473
• https://martinfowler.com/bliki/DomainDrivenDesign.html
• https://en.wikipedia.org/wiki/Domain-driven_design
• https://github.com/SAP/curated-resources-for-domain-driven-design/blob/main/ddd-kata.md
• https://medium.com/inato/an-introduction-to-domain-driven-design-386754392465