Add `AI_POLICY.md`

[evenstensberg]

We should have a policy that says how ai contributions is supposed to work with the project.

[evenstensberg]

In opensjf theres been discussion to put this in moderation, but i think this should be in the cla. lets await their working group feedback.

[ovflowd]

@evenstensberg can you link the discussion that you're referring to?

[evenstensberg]

Dont have the hard-link but I think it might reside in the collaboration space.

[evenstensberg]

Status: We will create our own AI policy that has rules saying people cant use AI on all of work in webpack (communicating, solving issues, commenting on issues etc)