Revised explanation of dependency injection

The explanation of dependency injection in the “Concepts Explained” section has been revised in order to offer a full web experience. Nevertheless the respective presentation has been preserved and may be downloaded and used offline.

Added “Concepts Explained” section

This new section is intended to explain magic concepts in easy words.

As a first explanation, a presentation regarding the concept of “Dependency Injection” and how to implement a respective container has been uploaded.