Edit Dynamicland section of front page, add comparison table

[sgwilym]

This PR edits the "How is Paper Programs related to Dynamicland?" section of the front page to address #32 a bit, and also adds a comparison table that makes it clear what Dynamicland Does that Paper Programs don't!

What other rows could be added to this table to dissuade anybody from thinking they could use Paper Programs as an alternative for working with Dynamicland? Three rows seems like a nice round figure.

After making all these PRs that kind of disparage Paper Programs I'm looking forward to contributing some more positive additions 😄

Screenshot:

[janpaul123]

Awesome, thank you! I really appreciate it.

Some other ideas for the table:

• Programs
  • PP: some explorations by the community
  • DL: rich library of small composite programs, larger projects in various domains, debugging tools, and Realtalk OS itself
• Interaction model
  • PP: programs on pieces of paper
  • DL: programs on pieces of paper, reprojected camera feeds, tables with electromagnets, and more modalities in progress

cc @osnr