Bundle all files to single JavaScript file, add development mode

Makefile

@@ -1,9 +1,10 @@
-.PHONY: help build clean update-npmjs-readme release publish
+.PHONY: help prod dev clean update-npmjs-readme release publish
 
 help:
 	@echo "Available targets:"
 	@echo "  - help:           Show this help message"
-	@echo "  - build:          Build the project"
+	@echo "  - prod:           Build the project in production mode"
+	@echo "  - dev:            Build the project in development mode"
 	@echo "  - clean:          Remove build artifacts"
 	@echo "  - release:        Create a new release version"
 	@echo "  - publish:        Publish the new version created with the release target"
@@ -11,13 +12,17 @@ help:
 node_modules:
 	npm install
 
-build: node_modules
-	npm run build
+prod: node_modules
+	npm run prod
+
+dev: node_modules
+	npm run dev
+	chmod +x dist/wtc-dev.mjs
 
 clean:
 	rm -r dist node_modules
 
-release: build
+release: prod
 	@read -p "Enter version bump (patch, minor, major): " bump && \
 	version=$$(npm version $$bump | grep -oP "(?<=v)[^']+") && \
 	echo "Version $$version created. Run 'make publish' to push the changes and publish the package."