A useful I found from a gist that I have been using recently

# COLORS
GREEN  := $(shell tput -Txterm setaf 2)
YELLOW := $(shell tput -Txterm setaf 3)
WHITE  := $(shell tput -Txterm setaf 7)
RESET  := $(shell tput -Txterm sgr0)


TARGET_MAX_CHAR_NUM=20
## Show help
help:

	@echo ''
	@echo 'Usage:'
	@echo '  ${YELLOW}make${RESET} ${GREEN}<target>${RESET}'
	@echo ''
	@echo 'Targets:'
	@awk '/^[a-zA-Z\-\_0-9]+:/ { \

		helpMessage = match(lastLine, /^## (.*)/); \

		if (helpMessage) { \

			helpCommand = substr($$1, 0, index($$1, ":")-1); \

			helpMessage = substr(lastLine, RSTART + 3, RLENGTH); \

			printf "  ${YELLOW}%-$(TARGET_MAX_CHAR_NUM)s${RESET} ${GREEN}%s${RESET}\n", helpCommand, helpMessage; \

		} \

	} \

	{ lastLine = $$0 }' $(MAKEFILE_LIST)

Which allows you to add a make help command to your Makefiles

## Generate Mobi file
mobi: clean_mobi create_foler_mobi

	gitbook mobi $(CURRENT_DIR_NOSLASH) $(MOBI_FULLNAME)

## Generate all files: website/pdf/epub/mobi
all: website pdf epub mobi