update preview image and readme

Author: tworkool

README.md

@@ -2,7 +2,7 @@
 The Sensebox Data Dashboard is a analytics dashboard for data collected from Senseboxes around the world (for more info on Senseboxes [follow this link](https://sensebox.de/en/))
 ![Dashboard Live Data Preview](https://github.com/tworkool/sensebox.data.dashboard/blob/main/webapp/src/assets/content/dashboard-preview.jpg)
 The motivation behind this project is mainly to create a better approach to visualising data collected from Senseboxes. The [Opensensemap](https://opensensemap.org/) is a great native approach for doing so, but in my opinion it could be improved from many perspectives.
-If you would like to use a published version of this dashboard, please visit his link: SOON TO BE ADDED
+If you would like to use a published version of this dashboard, please visit his link: [sensebox-data-dashboard.de](sensebox-data-dashboard.de)
 #### Motivation
 One prominent feature which will be implemented in the future, is a Map visualising different sensor data from multiple Senseboxes. The main focus is the development of a user-driven dashboard for managing the overview of data.