document make targets

fixes #4647

License: MIT
Signed-off-by: Steven Allen <steven@stebalien.com>

Rules.mk

@@ -142,14 +142,14 @@ help:
 	@echo ''
 	@echo 'TESTING TARGETS:'
 	@echo ''
-	@echo '  test                    - Run expensive tests'
-	@echo '  test_short              - Run short tests and short sharness tests'
-	@echo '  test_go_short'
-	@echo '  test_go_expensive'
-	@echo '  test_go_race'
+	@echo '  test                    - Run all tests'
+	@echo '  test_short              - Run short go tests and short sharness tests'
+	@echo '  test_go_short           - Run short go tests'
+	@echo '  test_go_expensive       - Run all go tests (and test build)'
+	@echo '  test_go_race            - Run go tests with the race detector enabled'
 	@echo '  test_go_megacheck       - Run the `megacheck` vetting tool'
-	@echo '  test_sharness_short'
-	@echo '  test_sharness_expensive'
+	@echo '  test_sharness_short     - Run short sharness tests'
+	@echo '  test_sharness_expensive - Run all sharness tests'
 	@echo '  test_sharness_race'
 	@echo '  coverage     - Collects coverage info from unit tests and sharness'
 	@echo