feat(makefile): add Makefile for goenv project

Makefile

@@ -0,0 +1,25 @@
+BIN_NAME := goenv
+PKG := github.com/ankitcharolia/goenv
+GOFILES := $(shell go list -f '{{range .GoFiles}}{{.}} {{end}}' ./...)
+
+build: bin/$(BIN_NAME)
+
+bin/$(BIN_NAME): $(GOFILES)
+	go build -o $@ $(PKG)
+
+build-cross: clean
+	GOOS=linux  GOARCH=amd64 go build -o dist/$(BIN_NAME)_amd64_linux $(PKG)
+	GOOS=linux  GOARCH=arm64 go build -o dist/$(BIN_NAME)_arm64_linux $(PKG)
+	GOOS=linux  GOARCH=arm go build -o dist/$(BIN_NAME)_arm_linux $(PKG)
+	GOOS=darwin GOARCH=amd64 go build -o dist/$(BIN_NAME)_amd64_darwin $(PKG)
+	GOOS=darwin GOARCH=arm64 go build -o dist/$(BIN_NAME)_arm64_darwin $(PKG)
+
+clean:
+	rm -rf bin dist
+
+deps:
+	go get -t ./...
+	go mod tidy
+
+# test:
+# 	go test -race -v ./...