ci: enhance Makefile with help command and update README for usage instructions

Author: liudger

Makefile

@@ -1,4 +1,10 @@
-.PHONY: setup lint test coverage
+.PHONY: setup lint test coverage help
+
+.DEFAULT_GOAL := help
+
+help: ## Show this help message
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | \
+		awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-15s\033[0m %s\n", $$1, $$2}'
 
 setup: ## Install dev dependencies and git hooks
 	uv sync --dev

README.md

@@ -150,9 +150,21 @@ To install all packages, including all development requirements:
 
 ```bash
 npm install
-uv sync --dev
+make setup
 ```
 
+### Makefile Targets
+
+A `Makefile` is provided for common development tasks. Run `make help` to
+see all available targets:
+
+| Command         | Description                          |
+|-----------------|--------------------------------------|
+| `make setup`    | Install dev dependencies & git hooks |
+| `make lint`     | Run all pre-commit hooks             |
+| `make test`     | Run tests                            |
+| `make coverage` | Run tests with coverage report       |
+
 As this repository uses [prek][prek] (a faster, Rust-based drop-in replacement
 for pre-commit), all changes are linted and tested with each commit. You can
 run all checks and tests manually, using the following command: