Revise the top-level and Setup sections to reflect OpenXR support.
Update existing headset setup instructions to cover both OpenXR and OpenVR setups, with OpenXR being enabled by default. Added a note at the end of the section explaining how to enable OpenVR support.
Add new sections for "Hololens 2" and "Meta Quest" headsets
Add entries for "Supported headsets" and "Supported XR modality" to each headset section
Add "How to use hand interaction" section
Update the Contributors section to acknowledge @LucasGandel and @sankhesh.
In the DeveloperGuide:
Remove obsolete build instructions.
Update Python snippet.
Add references to the documentation of associated VTK modules.
Add the "Mapping of Controller Action to VTK event" section.
In the README:
In the DeveloperGuide: