Improve Makefile targets and documentation (#7)

Makefile

@@ -1,11 +1,17 @@
-.PHONY=asset-pdf asset-revealjs assets
-.DEFAULT=assets
+.PHONY: asset-revealjs asset-pdf asset-html assets
+.DEFAULT_GOAL := help
 
-asset-pdf: 
+asset-html: ## Render HTML Webpage
+	quarto render asset-generation/my-html-page.qmd --output-dir ../docs/assets
+
+asset-pdf: ## Render PDF Document
 	quarto render asset-generation/my-pdf-file.qmd --output-dir ../docs/assets
 
-asset-revealjs:
+asset-revealjs: ## Render RevealJS Slides
 	quarto render asset-generation/my-revealjs-slides.qmd --output-dir ../docs/assets
 
-assets:
-	asset-revealjs asset-pdf
+assets:	asset-revealjs asset-pdf asset-html  ## Render all assets
+
+help:  ## Show help messages for make targets
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(firstword $(MAKEFILE_LIST)) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[32m%-18s\033[0m %s\n", $$1, $$2}'
+