Added paragraph about running Cryptomator using the .jar files within the buildkit.

This fixes #917
[ci skip]

README.md

@@ -59,6 +59,10 @@ mvn clean install -Prelease
 
 This will build all the jars and bundle them together with their OS-specific dependencies under `main/buildkit/target`. This can now be used to build native packages.
 
+### Start Cryptomator
+
+If you unzip the buildkit for your OS, you will find a launcher script with some basic settings. You might want to adjust these to your needs. To start Cryptomator, simply execute the launcher script from a terminal, e.g. `launcher-linux.sh`, if you're on a Linux system.
+
 ## License
 
 This project is dual-licensed under the GPLv3 for FOSS projects as well as a commercial license for independent software vendors and resellers. If you want to modify this application under different conditions, feel free to contact our support team.