Add AI policy

[tellypresence]

While it doesn't appear to have become a problem for the assimp project yet,a number of open source projects have put up AI (Artificial Intelligence) policies to help mitigate submission of "AI slop" PRs.

Recent discussions include

• Blender 3D tool AI Contributions Policy which in turn links to AI policies for other open source projects
• Github's own discussion

The main takeaway is that PRs where the submitter relied too heavily on AI tools and themselves

• don't understand the code
• haven't tested the PR

should be strongly discouraged

Could probably craft an AI policy for assimp from language used in the linked templates.

[kimkulling]

That is a good idea. I will try to prepare one. Or do you have something in mind already?