h5wasm cannnot find example file

[prjemian]

The new documentation provides a link to h5wasm and visualize one of our HDF5 files. The link is 404 (not found). It should not point into build products of the documentation but rather point to the GitHub repo source, available on-line. Here's the correct link.

https://raw.githubusercontent.com/nexusformat/definitions/main/manual/source/examples/python/simple_example_basic/simple_example_basic.nexus.hdf5