Update roadmap to clarify large data and workflows examples; add multi select groups and drilldown

[droumis]

This PR updates the public roadmap to clarify/generalize the targets concerning large data handling and domain workflow examples. It also adds the internally known desiderata of multiple selection groups and drilldown support.

Besides a couple of other wording/whitespace fixes, I've also removed the solicitation for funding via a private entity which is noncompliant with NumFOCUS fiscal sponsorship.

I apologize for the obfuscation caused by the word wrap limit update. I noticed it too late.

[droumis]

Problem with formatting. It was there before this PR. UPDATE: fixed

[jbednar]

Looks good! If you're reformatting the text anyway, please go all the way and simply remove the word wrapping, which should behave better for future diffs.