Improve Makefile help and implementation

This allows more granular tasks and composition.

Also improved the documentation.

Signed-off-by: Marco Franssen <marco.franssen@gmail.com>

Makefile

@@ -2,7 +2,7 @@ TARGET_BRANCH ?= main
 
 .PHONY: help
 help: ## Display this help.
-	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n"} /^[a-zA-Z_0-9-]+:.*?##/ { printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)
+	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n"} /^[a-zA-Z_0-9-]+:.*?##/ { printf "  \033[36m%-20s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)
 
 ##@ Linting:
 
@@ -15,10 +15,10 @@ lint-release: ## Lint the charts using chart-testing for release
 	@echo Linting charts…
 	@ct lint --config ct.yaml --target-branch $(TARGET_BRANCH)
 
-##@ Testing:
+##@ Testing: (ensure to run on dedicated test cluster)
 
-.PHONY: clean-lingering-resources
-clean-lingering-resources:
+.PHONY: clean-test-leftovers
+clean-test-leftovers: ## Cleans up any lingering resources in case tests fail massively
 	@echo Cleanup potential leftovers…
 	@-kubectl delete csidrivers.storage.k8s.io csi.spiffe.io \
 		&>/dev/null || true
@@ -30,17 +30,20 @@ clean-lingering-resources:
 		&>/dev/null || true
 
 .PHONY: test
-test: install-test-dependencies ## Run tests using Helm chart-testing (ensure to run on dedicated test cluster)
-	@echo Running tests…
-	@ct install --config ct.yaml
+test: install-test-deps test-charts test-examples ## Run all chart tests and example tests
 
-.PHONY: install-test-dependencies
-install-test-dependencies: ## Install test dependency resources
+.PHONY: install-test-deps
+install-test-deps: ## Install test dependency resources
 	@echo Installing test dependencies…
 	@.github/tests/pre-install.sh
 
-.PHONY: cleanup-test-dependencies
-cleanup-test-dependencies: ## Cleans up all test dependencies resources
+.PHONY: test-charts
+test-charts: ## Run tests on charts using Helm chart-testing
+	@echo Running tests…
+	@ct install --config ct.yaml
+
+.PHONY: cleanup-test-deps
+cleanup-test-deps: ## Cleans up all test dependencies resources
 	@echo Uninstalling test dependencies…
 	@helm uninstall -n cert-manager cert-manager 2>/dev/null || true
 	@kubectl delete ns cert-manager 2>/dev/null || true
@@ -59,4 +62,4 @@ test-example-%:
 	@echo
 
 .PHONY: test-examples
-test-examples: $(patsubst examples/%/values.yaml,test-example-%,$(wildcard examples/*/values.yaml)) ## Run helm install for and helm test for all the examples
+test-examples: $(patsubst examples/%/values.yaml,test-example-%,$(wildcard examples/*/values.yaml)) ## Run `helm install` and `helm test` for all the examples containing `run-tests.sh`