Makefile: implement make help

Makefile

@@ -1,8 +1,16 @@
 .PHONY: all
 all: build-binary build-container
 
+.PHONY: help
+help:
+	@echo 'Usage:'
+	@echo '  make <target>'
+	@echo ''
+	@echo 'Targets:'
+	@awk 'match($$0, /^([a-zA-Z_\/-]+):.*?## (.*)$$/, m) {printf "  \033[36m%-30s\033[0m %s\n", m[1], m[2]}' $(MAKEFILE_LIST) | sort
+
 .PHONY: clean
-clean:
+clean:  ## clean all build and test artifacts
 	# not sure if we should remove generated stuff
 	# keep the output directory itself
 	#-rm -rf output/*
@@ -11,22 +19,25 @@ clean:
 	sudo rm -rf /var/tmp/bib-tests
 
 .PHONY: test
-test:
+test:  ## run all tests - Be aware that the tests take a really long time
 	@echo "Be aware that the tests take a really long time"
 	@echo "Running tests as root"
 	sudo -E pip install --user -r test/requirements.txt
 	sudo -E pytest -s -v
 
+.PHONY: build
+build: build-binary  ## shortcut for build-binary
+
 .PHONY: build-binary
-build-binary:
+build-binary:  ## build the binaries (multiple architectures)
 	./build.sh
 
 .PHONY: build-container
-build-container:
+build-container:  ## build the bootc-image-builder container
 	sudo podman build --tag bootc-image-builder .
 
 .PHONY: push-check
-push-check: build-binary build-container test
+push-check: build-binary build-container test  ## run all checks and tests before a pushing your code
 	cd bib; go fmt ./...
 	@if [ 0 -ne $$(git status --porcelain --untracked-files|wc -l) ]; then \
 	    echo "There should be no changed or untracked files"; \