chore: add `check_format.yml` #5

	---
	name: check_format

	# yamllint disable-line rule:truthy
	on:
	workflow_dispatch:
	push:
	branches:
	- main
	pull_request:

	jobs:
	check_format:
	name: Check format
	runs-on: ubuntu-latest
	steps:
	- uses: julia-actions/setup-julia@v1
	with:
	version: 1.8
	- uses: actions/checkout@v4
	with:
	fetch-depth: 0

	- name: Install JuliaFormatter
	run: \|
	julia -e 'using Pkg; Pkg.add(PackageSpec(name="JuliaFormatter"))'

	- name: Format code
	run: \|
	git clean -f -x -d
	julia -e 'using JuliaFormatter; format(".", verbose=true)'

	- name: Fail if needs reformatting
	run: \|
	if [[ $(git status --porcelain) ]]; then
	echo "please reformat these files:"
	git status --porcelain=v1
	exit 1
	fi

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