Added remark to installation on MacOS #1783 (#1852)

* Added remark to installation on MacOS #1783

* Installing from update site: Hint for macOS users reviewed.

plugins/org.yakindu.sct.doc.user/src/user-guide/installation.textile

@@ -436,6 +436,8 @@ h2(#inst_installing_to_an_existing_eclipse_instance). Installing to an existing
 
 This chapter describes the steps that are needed to install YAKINDU Statechart Tools to an existing Eclipse instance. Let's assume you already have Eclipse up and running and now you want to install YAKINDU Statechart Tools as an additional software item (plugin).
 
+bq. *Please note:* On macOS, this only works if your _.app_ file is located in your _app_ folder.
+
 In the the _Help_ menu, select the _Install New Software_ menu item:
 
 !images/inst_eclipse_010_eclipse_menu_install_new_software.png(Selecting "Help → Install New Software" in the main menu)!