[Rust][DataFusion] Improve Examples in documentation

[asfimport]

It would be cool to have an example on the main README.md of datafusion (that appears on the crates.io homepage) that shows a prospective user what DataFusion offers.

e.g look at how tokio does it https://crates.io/crates/tokio)

I plan to lift the nice example from https://docs.rs/datafusion/3.0.0/datafusion/ ?

Reporter: Andrew Lamb / @alamb
Assignee: Andrew Lamb / @alamb

PRs and other links:

• GitHub Pull Request #9710

_{Note: This issue was originally created as ARROW-11969. Please see the migration documentation for further details.}

[asfimport]

Andrew Lamb / @alamb:
Issue resolved by pull request 9710
#9710