docs: Update design decisions with Platform.exit

DESIGN_DECISIONS.md

@@ -1,12 +1,21 @@
 # Design decisions
 
 ## Not using (de)compression in java
+
 The JDK jars contain files with symlinks in them, this is not properly supported by for example commons-compress.
 Also file permissions are not working, so files can't be executed.
 
-Therefor the choice has been made to just use os tools like unzip and tar on osx and linux. And there bundle this software on windows.
+Therefor the choice has been made to just use os tools like unzip and tar on osx and linux. And then bundle this
+software on windows.
 
 ## native-image folder
-The files generated by the agent in native-image are very os dependent, so we need a set for every os, the best solution 
-would be to set the `agentDir` property in the gluon plugin, however does not work. So we copy the files manually. First 
+
+The files generated by the agent in native-image are very os dependent, so we need a set for every os, the best solution
+would be to set the `agentDir` property in the gluon plugin, however does not work. So we copy the files manually. First
 in the `validate` phase and then we need to put it back manually.
+
+## Do not use Platform.exit
+
+JavaFX has a `Platform.exit` method that will terminate the application. This brings some issues on at lease OSX with
+the shutdown hook, as that will not fire. Therefore, we close the application by calling `close` on the main stage. This
+is implemented in `MainScreenController.exitApplication()`