Add link to nginx explanation

README.md

@@ -7,8 +7,8 @@ Pull the image. Replace the version number. If unknown look up the latest versio
 
 `docker pull fwelter/wilps_slide_index:<VERSION_NUMBER>`
 
-Run the image. Adjust the ports according to your setup. Most likly the containers needs to be put behind an 
-nginx or another webserver to ensure SSL encryption (see below for instructions).
+Run the image. Adjust the ports according to your setup. Most likly the containers needs to be put [behind an 
+nginx](https://gitlab.rrz.uni-hamburg.de/bay1620/wilps-related-items/#nginx) or another webserver to ensure SSL encryption.
 
 ```
 sudo docker run -p 8080:5000 \