Update screenshots in docu

docs/navigation-advanced.md

@@ -219,7 +219,7 @@ The purpose of contexts is to send objects to the micro frontend. You can do thi
 
 ## Profile
 
-<img src="https://github.com/SAP/luigi/blob/master/docs/assets/profile.png?raw=true" width="628">
+![Profile](assets/profile.jpg)
 
 The profile is a drop-down list in the top navigation that allows you to override the logout item content if authorization is already configured. You can also add links to Luigi navigation nodes.
 
@@ -240,7 +240,7 @@ profile: {
 
 ## Context switcher
 
-<img src="https://github.com/SAP/luigi/blob/master/docs/assets/context-switcher.png?raw=true" width="628">
+![Context switcher](assets/context-switcher.jpg)
 
 The context switcher is a drop-down element in the top navigation. It allows you to switch between a curated list of navigation elements such as Environments. To do so, add the **contextSwitcher** property to the navigation object. Find all the parameters you can use to configure it [here](navigation-parameters-reference.md#context-switcher).
 
@@ -273,7 +273,7 @@ contextSwitcher: {
 
 ## Product switcher
 
-<img src="https://github.com/SAP/luigi/blob/master/docs/assets/product-switcher.png?raw=true" width="704">
+![Product switcher](assets/product-switcher.jpg)
 
 The product switcher is window in top the navigation which allows you to switch between navigation elements displayed there. To add it to your application, include the **productSwitcher** property in your **navigation** object. You may also add any of the parameters listed [here](navigation-parameters-reference.md#product-switcher).
 
@@ -305,7 +305,7 @@ productSwitcher: {
 
 ## App switcher
 
-<img src="https://github.com/SAP/luigi/blob/master/docs/assets/app-switcher.png?raw=true" width="407">
+![App switcher](assets/app-switcher.jpg)
 
 The app switcher is a drop-down in top the navigation which allows you to switch between applications. To use it, add the **appSwitcher** property in your **navigation** object. You may also add any of the parameters listed [here](navigation-parameters-reference.md#app-switcher).
 
@@ -331,7 +331,7 @@ appSwitcher = {
 
 ## Tab navigation
 
-<img src="https://github.com/SAP/luigi/blob/master/docs/assets/tabnav.png?raw=true" width="710">
+![Tab navigation](assets/tabnav.jpg)
 
 Tab-style navigation in Luigi can be displayed directly above the micro frontend area, providing you with additional menu options. When you put tab navigation nodes into a [category](navigation-configuration.md#category), they will be rendered in a drop-down. Add this parameter to your configuration to create tab navigation nodes:
 

docs/navigation-configuration.md

@@ -34,7 +34,7 @@ There are three main elements to Luigi:
 3. Main content window which renders the micro frontend.
 
 
-![Navigation layout](assets/navigation-structure.png)
+![Navigation layout](assets/navigation-structure.jpg)
 
 
 ## First steps