InsightSoftwareConsortium/itkwidgets: itkwidgets 1.0 Alpha 11

What's Changed BUG: Use existing NGFF Zarr as-is by @thewtex in https://github.com/InsightSoftwareConsortium/itkwidgets/pull/533 Notebook testing by @thewtex in https://github.com/InsightSoftwareConsortium/itkwidgets/pull/534 DOC: Add notebook test badge to README by @thewtex in https://github.com/InsightSoftwareConsortium/itkwidgets/pull/535 Downsample label by @thewtex in https://github.com/InsightSoftwareConsortium/itkwidgets/pull/537 chore: bump itk-vtk-viewer version by @PaulHax in https://github.com/InsightSoftwareConsortium/itkwidgets/pull/538 Full Changelog: https://github.com/InsightSoftwareConsortium/itkwidgets/compare/v1.0a10...v1.0a1