Add note on versions of libraries and frameworks used in the workshop

README.md

@@ -60,12 +60,12 @@ and Visual Studio 2017.
 
 ```powershell
 # create a C:\gx-ws directory
-$wsFolder = "C:\gx-ws"
-New-Item -Path $wsFolder -ItemType Directory
-# download the zip-archive
-$client = New-Object System.Net.WebClient
-$client.DownloadFile("https://github.com/geoext/geoext3-ws/archive/master.zip", "$wsFolder/master.zip")
-# unzip the archive
+$wsFolder = "C:\gx-ws"
+New-Item -Path $wsFolder -ItemType Directory
+# download the zip-archive
+$client = New-Object System.Net.WebClient
+$client.DownloadFile("https://github.com/geoext/geoext3-ws/archive/master.zip", "$wsFolder/master.zip")
+# unzip the archive
 Expand-Archive -Path $wsFolder/master.zip -DestinationPath $wsFolder
 # install the chocolatey package manager
 # if you have Visual Studio 2010+ and the Nugetextension installed you can run the
@@ -87,6 +87,14 @@ If gitbook fails to install try running the following separately:
 npm install gitbook-cli -g
 ```
 
+## Library Versions
+
+During the workshop you will work with the following JavaScript libraries or frameworks:
+
+* OpenLayers ([4.6.5](https://github.com/openlayers/openlayers/releases/tag/v4.6.5)): http://openlayers.org/
+* ExtJS ([v6.2.0, GPL](https://www.sencha.com/legal/GPL/)): https://www.sencha.com/products/extjs/
+* GeoExt3 ([v3.1.0](https://github.com/geoext/geoext3/releases/tag/v3.1.0)): http://geoext.github.io/geoext3/
+
 ## Developing instructions
 
 For developing and enhancing the workshop.