Add `pre-commit`, `pre-commit` gh action, and update contribution guide #290

	# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
	# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions

	name: Init Config

	on:
	push:
	branches: master
	pull_request:
	branches: master

	jobs:
	build:
	timeout-minutes: 5
	runs-on: ubuntu-latest
	strategy:
	matrix:
	python-version: ['3.8', '3.9', '3.10', '3.11']

	steps:
	- uses: actions/checkout@v2

	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}

	- name: Lint with flake8
	run: \|
	pip install -U pip
	pip install flake8
	# stop the build if there are Python syntax errors or undefined names
	flake8 ./python/ngen_init_config --count --select=E9,F63,F7,F82 --show-source --statistics
	# exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
	flake8 ./python/ngen_init_config --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics

	- name: Installing ngen_init_config in python virtual environment
	run: \|
	# setup virtual environment
	python -m venv venv
	source ./venv/bin/activate
	pip install -U pip
	pip install "python/ngen_init_config[develop]"

	- name: List dependency versions
	run: \|
	source ./venv/bin/activate
	pip freeze

	- name: Testing ngen.init_config with pytest
	run: \|
	source ./venv/bin/activate
	pytest python/ngen_init_config

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