Add warning concerning AI-generated content

Author: jeremystretch

CONTRIBUTING.md

@@ -86,12 +86,16 @@ intake policy](https://github.com/netbox-community/netbox/wiki/Issue-Intake-Poli
 
 * In most cases, it is not necessary to add a changelog entry: A maintainer will take care of this when the PR is merged. (This helps avoid merge conflicts resulting from multiple PRs being submitted simultaneously.)
 
-* All code submissions should meet the following criteria (CI will enforce these checks):
+* All code submissions must meet the following criteria (CI will enforce these checks where feasible):
+  * Consist entirely of original work
   * Python syntax is valid
   * All tests pass when run with `./manage.py test`
   * PEP 8 compliance is enforced, with the exception that lines may be
       greater than 80 characters in length
 
+> [!CAUTION]
+> Any contributions which include AI-generated or reproduced content will be rejected.
+
 * Some other tips to keep in mind:
   * If you'd like to volunteer for someone else's issue, please post a comment on that issue letting us know. (This will allow the maintainers to assign it to you.)
   * Check out our [developer docs](https://docs.netbox.dev/en/stable/development/getting-started/) for tips on setting up your development environment.
@@ -117,8 +121,6 @@ We're always looking for motivated individuals to join the maintainers team and
 
 We generally ask that maintainers dedicate around four hours of work to the project each week on average, which includes both hands-on development and project management tasks such as issue triage. Maintainers are also encouraged (but not required) to attend our bi-weekly Zoom call to catch up on recent items.
 
-Many maintainers petition their employer to grant some of their paid time to work on NetBox. In doing so, your employer becomes eligible to be featured as a [NetBox sponsor](https://github.com/netbox-community/netbox/wiki/Sponsorship).
-
 Interested? You can contact our lead maintainer, Jeremy Stretch, at [email protected] or on the [NetDev Community Slack](https://netdev.chat/). We'd love to have you on the team!
 
 ## :heart: Other Ways to Contribute