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.

make/def.docker.mk

@@ -37,7 +37,7 @@ HOST_DOCKER_VOLUME              ?= $(HOST_COMPOSE_PROJECT_NAME)
 HOST_GID                        ?= $(HOST_UID)
 HOST_UID                        ?= 123
 HOST_STACK                      ?= $(filter host,$(firstword $(subst /, ,$(STACK))))
-MYOS_STACK                      ?= $(wildcard $(foreach stack_dir,$(STACK_DIR),$(stack_dir)/myos))
+MYOS_STACK                      ?= $(if $(filter . myos,$(MYOS)),$(realpath $(MYOS)/share/compose))
 MYOS_STACK_FILE                 ?= networks volumes
 RESU_DOCKER_REPOSITORY          ?= $(subst -,/,$(USER_COMPOSE_PROJECT_NAME))
 SHARE_DIR                       ?= . .. ~/.local/share /usr/local/share /usr/share