[Rust] [DataFusion] Integrate doc-comment crate to ensure readme examples remain valid

[asfimport]

As discussed at: #9710 (comment)

We can use the doc-comment crate to include snippets of Rust code from the readme in our doctest runs, ensuring that our documentation doesn't drift from reality as API changes are made.

Reporter: Ruan Pearce-Authers / @returnString
Assignee: Ruan Pearce-Authers / @returnString

PRs and other links:

• GitHub Pull Request #9749
• GitHub Pull Request #9754

_{Note: This issue was originally created as ARROW-12015. Please see the migration documentation for further details.}

[asfimport]

Andrew Lamb / @alamb:
Issue resolved by pull request 9749
#9749