Add Makefile and .app

Makefile

@@ -0,0 +1,45 @@
+TARGET = alacritty
+
+APP_NAME = Alacritty.app
+ASSETS_DIR = assets
+RELEASE_DIR = target/release
+APP_TEMPLATE = $(ASSETS_DIR)/osx/$(APP_NAME)
+APP_DIR = $(RELEASE_DIR)/osx
+APP_BINARY_DIR  = $(APP_DIR)/$(APP_NAME)/Contents/MacOS
+
+DMG_NAME = Alacritty.dmg
+DMG_DIR = $(RELEASE_DIR)/osx
+
+vpath $(TARGET) $(RELEASE_DIR)
+vpath $(APP_NAME) $(APP_DIR)
+
+all: help
+
+help: ## Prints help for targets with comments
+	@grep -E '^[a-zA-Z._-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
+
+binary: | $(TARGET) ## Build release binary
+$(TARGET):
+	@echo "Please build '$@' with 'cargo build --release'"
+
+app: | $(APP_NAME) ## Clone Alacritty.app template and mount binary
+$(APP_NAME): $(TARGET) $(APP_TEMPLATE)
+	@mkdir -p $(APP_DIR)
+	@cp -R $(APP_TEMPLATE) $(APP_DIR)
+	@cp $< $(APP_BINARY_DIR)
+	@echo "$@ created in $(APP_DIR)"
+
+dmg: | $(DMG_NAME) ## Pack Alacritty.app into .dmg
+$(DMG_NAME): $(APP_NAME)
+	@echo "Packing disk image..."
+	@hdiutil create $(DMG_DIR)/$(DMG_NAME) \
+		-volname "Alacritty" \
+		-fs HFS+ \
+		-srcfolder $(APP_DIR) \
+		-ov -format UDZO
+	@echo "$@ packed in $(APP_DIR)"
+
+.PHONY: app binary clean dmg
+
+clean: ## Remove all artifacts
+	-rm -rf $(APP_DIR)