Reorganize access section in README for clarity

readme.md

 # Urban Geoinformatics Lab @HFT Stuttgart Web Page
 Website for Geoinformatic Research Group (Prof. Coors)
-#### URL (1): https://ugl.hft-stuttgart.de/
-#### URL (2): https://transfer.hft-stuttgart.de/pages/ugl/website/
+
+## Access
+- URL (1): https://ugl.hft-stuttgart.de/
+- URL (2): https://transfer.hft-stuttgart.de/pages/ugl/website/
+- Access with Keyword filter using ?keyword=<keyword>, for example, https://ugl.hft-stuttgart.de/?keyword=CityGML
+- Access with Contact Person filter using ?author=<name>, for example, https://ugl.hft-stuttgart.de/?author=Joe
+- You can also combine filters: https://ugl.hft-stuttgart.de/?keyword=Water&author=Joe
 
 # How to Add contents?
 1. Contact admin (Joe/Sven/Habib) to get developer access.