SWPROT-8953: build: Add hints in helper script

This part is not yet documented in docs,
it will be done after the deduplication of UnifySDK

For the record the whole zpc code can be built using this oneliner:

  time docker build https://github.com/SiliconLabsSoftware/z-wave-protocol-controller.git#main # 17min

Origin: #35
Signed-off-by: Philippe Coval <philippe.coval@silabs.com>

Author: rzr

helper.mk

@@ -10,6 +10,8 @@ default: help all/default
 SELF?=${CURDIR}/helper.mk
 
 project?=z-wave-protocol-controller
+url?=https://github.com/SiliconLabsSoftware/z-wave-protocol-controller
+
 # Temporary workaround for:
 # https://gitlab.kitware.com/cmake/cmake/-/issues/22813#note_1620373
 project_test_dir?=applications
@@ -91,17 +93,31 @@ export CMAKE_TARGET_TRIPLE
 endif
 
 
-help: README.md
-	@cat $<
+help: ./helper.mk
+	@echo "# ${project}: ${url}"
+	@echo "#"
+	@echo "# Usage:"
+	@echo "#  ${<D}/${<F} setup # To setup developer system (once)"
+	@echo "#  ${<D}/${<F} VERBOSE=1 # Default build tasks verbosely (depends on setup)"
+	@echo "#  ${<D}/${<F} # For more info"
+	@echo "#"
+
+help/all: README.md NEWS.md
+	@echo "# ${project}: ${url}"
 	@echo ""
-	@echo "# Available rules at your own risk:"
+	@head $^
+	@echo ""
+	@echo "# Available helper.mk rules at your own risk:"
 	@grep -o '^[^ ]*:' ${SELF} \
 		| grep -v '\$$' | grep -v '^#' | grep -v '^\.' \
 		| grep -v '=' | grep -v '%'
-	@echo ""
+	@echo "#"
 	@echo "# Environment:"
-	@echo "# PATH=${PATH}"
+	@echo "#  PATH=${PATH}"
+	@echo "#  version=${version}"
 	@echo ""
+	@echo ""
+
 
 setup/debian: ${CURDIR}/docker/target_dependencies.apt ${CURDIR}/docker/host_dependencies.apt
 	cat /etc/debian_version
@@ -168,7 +184,7 @@ ${PLANTUML_JAR_PATH}:
 	${sudo} install -d ${plantuml_dir}
 	${sudo} install ${plantuml_filename} ${plantuml_dir}/
 	rm -v ${plantuml_filename}
-	@echo "# %@: Please adapt env to:"
+	@echo "# $@: Please adapt env to use:"
 	@echo "# export PLANTUML_JAR_PATH=${plantuml_dir}/${plantuml_filename}"
 
 setup/plantuml: ${PLANTUML_JAR_PATH}
@@ -290,13 +306,18 @@ prepare/docker: Dockerfile prepare
 	@echo "# ${project}: log: $@: done: $^"
 
 docker_workdir?=/usr/local/opt/${project}
+docker_branch?=main
+docker_url?=${url}.git\#${docker_branch}
 
 docker/%: Dockerfile
 	time docker run "${project}:latest" -C "${docker_workdir}" "${@F}"
 
 test/docker: distclean prepare/docker docker/help docker/test
 	@echo "# ${project}: log: $@: done: $^"
 
+test/docker/build:
+	time docker build -t "${project}:${docker_branch}" ${docker_url}
+
 docs: ./scripts/build/build_documentation.py doc ${PLANTUML_JAR_PATH} configure
 	@echo "# export PLANTUML_JAR_PATH=${plantuml_dir}/${plantuml_filename}"
 	@echo "$@: PLANTUML_JAR_PATH=${PLANTUML_JAR_PATH}"