Start reorganizing documentation with focus on simplicity.
Reworked parts of the tutorial
Moved tools to Advanced topic, included simple setting up tools in Installation. Reworked CLI tool to print a template when no cli-config.php is defined.
Worked on the Getting Started Guide
Remove models/database first tutorials for now
Move all classes to src/ in tutorial rather than in entities/
Huge refactoring of the Getting Started Tutorial to allow for an earlier success with the simple Product entity.
Add simpler section for 2.4 CLI integration
Fix link in docs
Fix DDC-2090
Merge pull request #619 from FabioBatSilva/DDC-2090

[DDC-2090] Fix MultiTableUpdateExecutor with query cache
Second cache level POC
First round of refactory
Fix factory method name