Add example extension to showcase slash commands (#16300)

This PR adds an example extension to showcase how to write slash
commands in an extension.

Release Notes:

- N/A

Marshall Bowers committed 2y ago

5a30e298483717e32b9dc6bad8bd2fb2c7d25294

Parent: 03b843e

Committed by GitHub <noreply@github.com> on 8/15/2024, 4:26:13 PM