Update homepage carousel - Vitessce slide

[tsliaw]

• Update text to:
  Title:
  Explore spatial single-cell data with Vitessce visualizations
  Description:
  View multi-modal single-cell resolution measurements with reusable interactive components such as a scatterplot, spatial+imaging plot, genome browser tracks, statistical plots and controller components.
• Update button link to link
• Update image to google drive image

@keller-mark or @ilan-gold Let me know if any of this information needs to be edited. Image is from the link Nils provided in Slack, but feel free to change the image/link to fit what's preferred (just comment in this issue if there needs to be changes). Homepage carousel requirement doc for reference.

[ilan-gold]

I think what we have looks good. Oxford comma after "statistical plots" would make me happy, but not a blocker haha