EN/CityGML-Tutorial.md

@@ -3,10 +3,10 @@
 [Chapter 1: Introduction CityGML](./CityGML-Tutorial/chapter 1: Intro CityGML)
 
 [Chapter 2: Building Module](./CityGML-Tutorial/chapter 2: Building)    
-<details><summary>Click to expand</summary>
-- [Chapter 2.1 Building LoD 1](./CityGML-Tutorial/chapter 2: Building/LoD 1)
-- [Chapter 2.2 Building LoD 1 with attributes](./CityGML-Tutorial/chapter 2: Building/LoD 1 with attributes)
-- [Chapter 2.3 Building LoD 2](./CityGML-Tutorial/chapter 2: Building/LoD 2)
+<details><summary>Click to expand</summary>  
+- [Chapter 2.1 Building LoD 1](./CityGML-Tutorial/chapter 2: Building/LoD 1)  
+- [Chapter 2.2 Building LoD 1 with attributes](./CityGML-Tutorial/chapter 2: Building/LoD 1 with attributes)  
+- [Chapter 2.3 Building LoD 2](./CityGML-Tutorial/chapter 2: Building/LoD 2)  
 </details>  
 
 [Chapter 3: Land use]()