applying reviewer suggestions

Co-authored-by: yubiuser <yubiuser@users.noreply.github.com>
Signed-off-by: Adam Warner <github@promofaux.dev>

Author: PromoFaux

AGENTS.md

@@ -34,7 +34,7 @@ The official Pi-hole Docker image. It packages FTL, the core scripts and the web
 - Run `bash test/run.sh` before committing.
 - Use Unix line endings (LF); shell scripts in this image run under the container's shell, not Windows.
 - Code is licensed under the EUPL 1.2; contributions must be compatible.
-- Environment variables are the public interface of this image. Document any new or changed variable in the README, and keep backwards compatibility unless a break is explicitly agreed.
+- Environment variables are the public interface of this image. Document any new or changed variable with a PR against the [docs repo](https://github.com/pi-hole/docs) (`docs/docker/configuration.md`), not the README; the full env var reference was deliberately moved out of the README once it grew too long. Keep backwards compatibility unless a break is explicitly agreed.
 - Stability comes before features; this image runs unattended on many systems.
 - The correct project spelling is "Pi-hole" (capital P, lowercase h, hyphen).
 
@@ -46,7 +46,7 @@ The official Pi-hole Docker image. It packages FTL, the core scripts and the web
 
 ## Common pitfalls
 
-- Changing environment variable behaviour without updating the README and tests.
+- Changing environment variable behaviour without updating the docs repo and tests.
 - Adding packages to the image without considering size and multi-arch availability.
 - Forgetting the DCO sign-off on commits.
 - Assuming host paths or Docker Desktop specifics; the image must work on plain Linux Docker and compose.