Merge branch 'docs-page_pool-tweaks-and-updates'

Jakub Kicinski says:

====================
docs: page_pool: tweaks and updates

I'm hoping to start feeding our docs into the AI review tools, instead
of maintaining a separate repo with review prompts. To experiment with
that we have to refresh the docs a little bit.

This set exclusively focuses on the page pool API. First patch is
a straightforward fix for information which is now out of date.
Second one attempts to clarify the NAPI linking requirements.
Third drops the dedicated section about the stats; the document
is primarily developer-facing and the stats should require no
development effort in most cases. Last but not least minor
API cleanup.
====================

Link: https://patch.msgid.link/20260526155722.2790742-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>