move the stack catalogue out of the framework

stack/ and docker/ now live in the myos-stacks project (extracted with their
history). What the framework itself needs stays here:
- stack/myos/*.yml            -> share/compose/
- docker/myos/                -> share/docker/myos/
- docker/compose/             -> dropped, docker compose >= 2.24.4 is now required

Residues fixed along the way: DOCKER_IMAGES scanned a hardcoded ./docker,
include.mk filtered a hardcoded stack/*.mk, and docker-image-myos expanded an
undefined MYOS_DOCKER_IMAGES on every up/build.

README and CHANGELOG rewritten: they still documented make host,
host-certbot-* and user-config, all removed when the catalogue was split out.

spec/golden/expected/host-print-stack-dir.txt

@@ -1,2 +1,2 @@
-STACK_DIR @MYOS@/stack @HOME@/.local/share/myos/stack @WD@/stack
+STACK_DIR @HOME@/.local/share/myos/stack @WD@/stack
 [exit 0]