Update README.md #123

	name: format
	on:
	push:

	jobs:
	update:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- uses: cachix/install-nix-action@v20
	with:
	github_access_token: ${{ secrets.GITHUB_TOKEN }}
	- name: nixfmt
	run: "nix develop --command nixfmt flake.nix"
	- name: black
	run: "nix develop --command black --safe ."
	- name: commit and push
	run: \|
	if git diff --exit-code; then
	echo 'no changes!'
	else
	git config user.name 'GitHub Actions'
	git config user.email '[email protected]'
	git add .
	git commit -am "format"
	git push
	fi

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