Updated doc

README.md

 # RegionChooser
 
-[RegionChooser](https://transfer.hft-stuttgart.de/gitlab/hft_gitlab/regionchooser) is a Java project. Its graphical interface allows to extract a specific region from [CityGML](https://www.opengeospatial.org/standards/citygml) and save it as a smaller CityGML file.
+[RegionChooser](https://transfer.hft-stuttgart.de/gitlab/hft_gitlab/regionchooser){target=_blank} is a Java project. Its graphical interface allows to extract a specific region from [CityGML](https://www.ogc.org/standards/citygml){target=_blank} and save it as a smaller CityGML file.
 
 ![RegionChooserScreenshot](region_chooser_screenshot.png)
 
 It uses:
 
-* Java 8
+* [Java 8](https://simstadt.hft-stuttgart.de/getting-started/install-software/#java-8){target=_blank}
 * JavaFX
-* [Openlayers](https://openlayers.org/)
+* [Openlayers](https://openlayers.org/){target=_blank}
 
-RegionChooser was developed during [SimStadt & SimStadt II](https://www.hft-stuttgart.de/forschung/projekte/aktuell/simstadt-20)  projects.
+RegionChooser was developed during [SimStadt & SimStadt II](https://www.hft-stuttgart.de/forschung/projekte/aktuell/simstadt-20){target=_blank}  projects.
 
 ## Installation
 
-`mvn clean package`
+The easiest way to install RegionChooser is to [install SimStadt](https://simstadt.hft-stuttgart.de/getting-started/install-software/#simstadt){target=_blank}.
+
+RegionChooser executables are packaged inside SimStadt.zip file.
 
 ## Usage
 
-`RegionChooser.bat` in Windows
-`./RegionChooser.sh` in Linux
-`./RegionChooser.command` in macOS
+### Select a repository
+
+You first need to run SimStadt in order to select a [repository](https://simstadt.hft-stuttgart.de/getting-started/repository-structure/#repository){target=_blank}. Once a repository is selected, SimStadt can be closed.
+
+### Start RegionChooser
+
+* `RegionChooser.bat` in Windows
+* `./RegionChooser.sh` in Linux
+* `./RegionChooser.command` in macOS
+
+## Development
+
+In order to compile, test and install RegionChooser into your local Maven repository:
+
+```bash
+git clone https://transfer.hft-stuttgart.de/gitlab/hft_gitlab/regionchooser.git
+cd regionchooser
+mvn clean install
+```
+
+The RegionChooser jar will then be available to SimStadt for packaging, when a SimStadt+RegionChooser bundle is created.
 
 ## Author
 
-Eric Duminil, [HfT Stuttgart](https://www.hft-stuttgart.de/)
+Eric Duminil, [HfT Stuttgart](https://www.hft-stuttgart.de/){target=_blank}
 
 ## Contributors
 
-Matthias Betz, [HfT Stuttgart](https://www.hft-stuttgart.de/)
+Matthias Betz, [HfT Stuttgart](https://www.hft-stuttgart.de/){target=_blank}
 
 ## License
-[MIT](https://choosealicense.com/licenses/mit/)
+[MIT](https://choosealicense.com/licenses/mit/){target=_blank}