Docker: Move files to the top directory.

This removes symlinks which are particularly troublesome on
Win32 systems. This fixes #104

Makefile

@@ -0,0 +1,35 @@
+export SPEC ?= spec
+SPEC_FILE = $(subst ../,, $(SPEC))
+export RUBY_IMAGE ?= ruby:3.1.2-slim
+
+.PHONY: up
+up:
+	docker-compose up
+
+.PHONY: down
+down:
+	docker-compose down
+
+.PHONY: test
+test: rspec
+
+.PHONY: ssh
+ssh:
+	docker-compose run lib bash
+
+.PHONY: install
+install:
+	docker-compose run lib bin/setup
+
+.PHONY: console
+console:
+	docker-compose run lib bin/console
+
+.PHONY: rspec
+rspec:
+	docker-compose run lib bin/rspec ${SPEC_FILE}
+
+.PHONY: setup
+setup:
+	docker-compose build --build-arg RUBY_IMAGE=${RUBY_IMAGE}
+	docker-compose run lib bin/setup

.docker/readme.md → README.Docker.md

@@ -1,20 +1,11 @@
 ## Docker
 
-This directory is only meant to be used for development, and contains some
+This Docker image is only meant to be used for development, and contains some
 necessary setup to spin up docker containers with multiple ruby environment.
 
 ### Setup
 
-Before doing anything, you might want to create a symlink to the docker file and
-Makefile. This would allow you to avoid some of the unnecessary work related to
-the file paths To do that run the following from the root of the project.
-
-```
-ln -sf .docker/Makefile .
-ln -sf .docker/docker-compose.yml .
-```
-
-By default it usages the most recent ruby version for docker environment, but if
+By default it uses the most recent ruby version for docker environment, but if
 you want to run it in any specific version then you can set it up by exporting
 `RUBY_IMAGE` environment variable in your shell:
 

docker-compose.yml

@@ -0,0 +1,14 @@
+version: "3"
+
+services:
+  lib:
+    build:
+      context: .
+      dockerfile: ./Dockerfile
+
+    volumes:
+      - .:/workspace:z
+      - bundle:/bundle:z
+
+volumes:
+  bundle: