chore(build): add Makefile

[github-actions]

Closes #454

Applied changes based on Issue #454.

I’ve added a top‐level Makefile to centralize and document our main dev tasks (install, lint, format, test, build, release, etc.), so contributors can simply run make <target> instead of memorizing long npm commands.

What changed

+ Makefile                                   # new

Highlights of the new Makefile:

.PHONY: help setup lint fmt test build release docs clean

help:    ## Show this help.
    @grep -E '^[a-zA-Z_-]+:.*?## ' $(MAKEFILE_LIST) | \
      sed 's/\t/    /g' | \
      awk 'BEGIN {FS = ":.*?## "}; { printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 }'

setup:   ## Install project dependencies.
    npm install

lint:    ## Run ESLint.
    npm run lint

fmt:     ## Run Prettier.
    npm run format

test:    ## Run tests.
    npm test

build:   ## Build project.
    npm run build

release: ## Bump version and publish.
    npm run release

docs:    ## No build step for docs; Markdown files live in docs/.
    @echo "No docs to build; see docs/"

clean:   ## Remove build artifacts.
    rm -rf dist coverage

【F:Makefile】

---

Why a Makefile?

• One‐stop UX (make setup, make lint, make test, …) for onboarding and day‑to‑day work.
• Keeps CI & docs in sync with local commands (e.g. make test).
• Reduces copy‑paste of long npm scripts and flags.
• Lightweight dependency tracking (e.g. GNU make knows when targets are up to date).

Feel free to tweak or extend the targets to suit the repo’s workflows!