Improve README

[jzy3d]

Readme should contain info

• how to get VTK as deployed on Maven central
• how the project is organized
• where the binaries come from

Import VTK from Maven

<dependency>
	<groupId>ch.unibas.cs.gravis</groupId>
	<artifactId>vtkjavanativesall</artifactId>
	<version>0.1.1</version>
</dependency>

This brings VTK 9.1 libraries for Windows, Linux and macOS+Intel (M1 will come later). It also brings JOGL and Glugen 2.4-rc4.

Unpacking and loading native libraries requires this line at the beginning of a program

VtkNativeLibraries.initialize(new File(System.getProperty("java.io.tmpdir")));

Which identifies the OS and CPU in order to extract the native libraries from the Jar suitable for this OS/CPU into the temporary directory.

How the project is organized

Existing doc

Reference to binaries

https://github.com/jzy3d/vtk-java-wrapper