Refactoring: Changed to summer 2025, hide chapter 6-15, added installation...

Refactoring: Changed to summer 2025, hide chapter 6-15, added installation guide, added folder description, created subfolders, deleted unused files

README.md

 # Introduction to Quantum Computing - Lecture notes
 
 Lecture note for the lecture "Introduction to Quantum Computing" by Dominique Unruh at RWTH Aachen.
+
+
+## Installation guide
+
+This guide is for VS Code. There may be other extensions for other development environments.
+
+### 1. Install Quarto  
+Download and install Quarto from the official website:  
+<https://quarto.org/docs/get-started/>
+
+### 2. Install the VS Code extension  
+Install the Quarto Extension for Visual Studio Code:  
+https://quarto.org/docs/get-started/  
+You can also find it in the Extensions tab by searching for `"Quarto"`.
+
+### 3. Preview the script  
+To live-preview the project, use the following command in your terminal:  
+`"quarto preview index.qmd"`  
+This opens the preview directly in the browser, the option `"--no-browser"` prevents this. 
+
+### 4. Render the script
+To render the entire project to .pdf and html use:  
+`"quarto render --to all"`  
+The output will be generated in the _book folder.
+
+
+## Project structure 
+
+The main components of the project are:
+
+### `_quarto.yml`
+This is the main configuration file for your project. It contains:
+- **Title**, **version**, **authors** and other metadata
+- The **structure** of the script is under the `chapters:` section
+
+You can **toggle chapter visibility** by commenting/uncommenting lines using `#`. This is useful for revealing content gradually throughout the semester.
+
+### `index.qmd`
+This file contains the **introduction** of the script.  
+It must be located in the same directory as the `quarto.yml` file.
+
+### `content/`
+This folder contains all the **chapters** of the script, as individual `.qmd` files.
+
+### `content/img/`
+Subfolder that holds all **images** used throughout the script.
+
+### `_extensions/`
+This folder includes any **custom Quarto extensions** that add functionality or styling to your project.
+
+### `_book/`
+This is the **output folder** generated by Quarto after rendering.  
+It contains the final script in the formats **HTML** and **PDF**.