Add example-driven documentation for the kernel's generic linked list
data structure. This includes discussion of situations where linked
lists are likely inappropriate, and references to further reading.
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://lore.kernel.org/r/20250714-linked-list-docs-v3-1-56c461580866@collabora.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
