Add an example demoing rewrite-clj.

[jwhitlark]

Please answer the following questions and leave the below in as part of your PR.

• [X] I have read the developer documentation.

No, this is an example.

• [X] This PR corresponds to an issue with a clear problem statement.

Not a code change

• [X] This PR contains a test to prevent against future regressions

Not a code change

• [X] I have updated the [Unreleased] section of the CHANGELOG.md file with a link to the addressed issue.

[jwhitlark]

@PEZ Please let me know if there's any more changes needed.

[jwhitlark]

Should all be fixed.

[PEZ]

Awesome. I think it is worth a mention in examples/README.md as well. 😄