Update repo:

* add README
* add screenshot

Author: Armin Schrenk

README.md

@@ -0,0 +1,10 @@
+javafx-helloworld
+=================
+
+This project is a small [JavaFX](https://openjfx.io/) app for testing purposes.
+It provides for each main OS (x64/x86 arch) a simple window application to see, if the JavaFX framework is functional under the operating system.
+The app is distributed with its own JVM and executable, thus no preinstalled JDK is required.
+
+Screenshot how it should look like (Windows):
+
+![Message, Textbox and Button in a Window](screenshot-win.png)