PR summary

Because the default is Base64-encoded frames of PNGs, this should save a substantial amount of space in the resulting docs. We may want to increase the bitrate slightly, though most of the videos seem clear enough to me.

This currently depends onsphinx-gallery/sphinx-gallery#1243 andsphinx-contrib/video#36.

These results are probably on the upper end, depending on if we change the bitrate, but disk usage is reduced substantially:

485Mhtml/377Mdoc/build/html/

That's 108M of savings, or 22% of the original disk usage.

PR checklist

• [n/a] "closes #0000" is in the body of the PR description tolink the related issue
• [n/a] new and changed code istested
• [n/a]Plotting related features are demonstrated in anexample
• [n/a]New Features andAPI Changes are noted with adirective and release note
• Documentation complies withgeneral anddocstring guidelines