Implemented the docker build and housekeeping workflows in the Makefile file.

Makefile

@@ -0,0 +1,51 @@
+# --- IMPORTS ---
+
+# Imports environment variables.
+environment_vars ?= .env
+
+include $(environment_vars)
+export $(shell sed 's/=.*//' $(environment_vars))
+
+# --- ARGUMENTS ---
+
+override tag?=${DOCKER_IMAGE_TAG}
+override platform?=${DOCKER_IMAGE_PLATFORM}
+override config?=${SWIFT_BUILD_CONFIGURATION}
+
+# --- BUILDING ---
+
+build: build-image remove-image ## Build this package against a Swift docker instance.
+
+build-image:
+	@docker run \
+		--rm \
+		--volume ${PWD}:${DOCKER_VOLUME_TARGET} \
+		--workdir ${DOCKER_VOLUME_TARGET} \
+		--platform ${platform} \
+		${DOCKER_IMAGE_NAME}:${tag} \
+		swift build --configuration ${config}
+
+remove-image: 
+	@docker rmi ${DOCKER_IMAGE_NAME}:${tag}
+
+# --- HOUSEKEEPING ---
+
+remove-images: ## Remove all outstanding Swift docker images.
+	@docker images --all | grep ${DOCKER_IMAGE_NAME} | awk '{print $$3}' | xargs docker rmi --force
+
+clean: ## Clean the build artifacts for the package. 
+	@swift package clean
+
+reset: ## Reset the build folder for the package.
+	@swift package reset
+
+# --- HELP ---
+
+# Outputs the documentation for each of the defined tasks when `help` is called.
+# Reference: https://marmelab.com/blog/2016/02/29/auto-documented-makefile.html
+.PHONY: help
+
+help: ## Prints the written documentation for all the defined tasks.
+	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}' $(MAKEFILE_LIST)
+
+.DEFAULT_GOAL := help