feat: let docker compose find its own file

README.md

@@ -38,6 +38,17 @@ SHELL_COMPLETIONS_DIR_FISH=~/.config/fish/completions \
 
 `SHELL_COMPLETIONS_DIR` writes every shell into one directory instead.
 
+## the compose file
+
+`ahab` does not pass `-f`. docker compose finds the file itself, so set
+docker's own `COMPOSE_FILE` when it is not in the working directory, including
+its `base.yaml:override.yaml` form. A project's `.env` is a good place for it,
+since docker reads that too:
+
+```
+COMPOSE_FILE=docker/docker-compose.yaml
+```
+
 ## compose
 
 Wrappers around the matching `docker compose` call, plus `exec` and `bash`
@@ -89,7 +100,6 @@ from the git `origin` remote.
 
 Currently `ahab` respects the following environment variables.
 
-- `COMPOSE_FILE`: control which docker-compose file is used - defaults to `docker/local/docker-compose.yaml`
 - `AHAB_DJANGO_CONTAINER`: control which compose service is used for sending django commands - defaults to `django`
 - `AHAB_POSTGRES_CONTAINER`: control which compose service is used for sending postgres commands - defaults to `db`
 - `AHAB_LINK_ROOT`: root of the out-of-repo store `ahab link` moves paths into - defaults to `${XDG_DATA_HOME:-$HOME/.local/share}/ahab`