Return wind generation from spectra examples

[alizma]

This got deleted in some iteration of cleaning, but should exist as a basic utility. Provided the appropriate spectra, the examples should illustrate the associated 3D field of random fluctuations in wind (see Figure 6 of the original DRD paper). This should have two examples:

• [x] dumping output to VTK to be visualized in Paraview (old code)
• [x] visualized directly in Python

The latter would be easiest in Plotly, but decent alternatives are PyVista and Mayavi, though I'm not sure how well these integrate with Sphinx and whether or not they would preserve interactivity...

[alizma]

This functionality now exists in two example notebooks and Plotly can be used to recreate the desired random wind field from a pre-trained DRD model. However, 3 issues remain for these examples to be integrated appropriately into the rest of the documentation:

• [x] set-up the correct Sphinx extensions for Plotly to render and be interactive
• [x] pre-rendered Plotly results in huge Jupyter notebooks, dumping all of the associated data into an HTML page is necessary for Sphinx
• [x] the current Plotly calls are going to be re-used every time for one of these examples (3 subplots of x, y, z fields and 1 for magnitude), move them to some utility

[alizma]

All tasks completed as of merge.