src/content/tutorial
│
├── meta.md # Tutorial metadata
│
└── lesson-1 # Lesson in root! No part or chapter.
   ├── content.md
   ├── _files
   └── _solution

src/content/tutorial
│
├── meta.md # Tutorial metadata
│
└── part-1
    └── lesson-1 # Lesson in part! No chapter.
        ├── content.md
        ├── _files
        └── _solution

src/content/tutorial
├── meta.md # Tutorial
├── lesson-1 # Lesson
└── part-1 # Part

> Error: Cannot mix lessons and parts in a tutorial. Either remove the parts or move root level lessons into a part.

src/content/tutorial
├── meta.md # Tutorial
└── part-1 # Part
    ├── lesson-1 # Lesson
    └── chapter-1 # Chapter

> Error: Cannot mix lessons and chapters in a part. Either remove the chapter from 1-part or move the lessons into a chapter.

src/content/tutorial
├── meta.md # Tutorial
│
├── part-1 # Part with lessons
│   └── lesson-1 # Lesson
│
└── part-2 # Part with chapters
    └── chapter-1 # Chapter