Finish "contributing" module in documentation, and update readme #19

	name: Check for typing/linting/formatting errors

	on:
	pull_request:
	types: [opened, synchronize]

	jobs:
	ci:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@v4
	with:
	# Make sure the actual branch is checked out when running on pull requests
	ref: ${{ github.head_ref }}
	# This is important to fetch the changes to the previous commit
	fetch-depth: 0
	- name: Install system dependencies
	run: sudo apt-get install -y libgmp-dev libmpfr-dev libmpc-dev
	- name: Setup PDM
	uses: pdm-project/setup-pdm@v4
	- name: Install dependencies
	run: pdm install
	- name: Check for formatting errors
	run: pdm run format-check
	- name: Check for linting errors
	run: pdm run lint-check
	- name: Check for type errors
	run: pdm run check-types

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