chore: initialize Go module and project scaffold

Makefile

@@ -0,0 +1,27 @@
+BINARY=divad
+BUILD_DIR=build
+
+.PHONY: all build run test lint vet clean
+
+all: lint vet build
+
+build:
+	go build -o $(BUILD_DIR)/$(BINARY) ./cmd/divad
+
+run: build
+	./$(BUILD_DIR)/$(BINARY)
+
+test:
+	go test -race -count=1 ./...
+
+lint:
+	golangci-lint run ./...
+
+vet:
+	go vet ./...
+
+clean:
+	rm -rf $(BUILD_DIR)/
+
+tidy:
+	go mod tidy