docs: hacking: Define policy forbidding use of AI code generators

docs: hacking: Define policy forbidding use of AI code generators

This policy is a copy of what QEMU project is using [1] as there is no
reason to use different policy, only modification is changing the
project name and link to DCO.

[1] <https://www.qemu.org/docs/master/devel/code-provenance.html#use-of-ai-content-generators>

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Jim Fehlig <jfehlig@suse.com>