Add help to Makefile

Author: necrophonic

Makefile

@@ -1,12 +1,12 @@
-platforms = windows/amd64 darwin/amd64 linux/amd64
+PLATFORMS := windows/amd64 darwin/amd64 linux/amd64
 package = cmd/pre-commit/main.go
 binary = build/pre-commit
 
 help:
-	@ echo "See Makefile for options"
+	@grep -E '^[a-zA-Z0-9_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
 
-compile:
-	@ for platform in $(platforms); do 										  \
+compile: clean ## Build binaries for all platforms defined in $PLATFORMS
+	@ for platform in $(PLATFORMS); do 										  \
 		platform_split=($${platform//\// }); 								  \
 		GOOS=$${platform_split[0]}; 										  \
 		GOARCH=$${platform_split[1]}; 										  \
@@ -17,4 +17,6 @@ compile:
 		echo "Build for $$platform -> $$output_name";						  \
 		env GOOS=$$GOOS GOARCH=$$GOARCH go build -o $$output_name $(package); \
 	done
-	
+
+clean: ## Cleanup build artifacts and remove build/
+	rm -rf build/