Update headlines in intro.md #29

	name: deploy-book

	# Only run this when the master branch changes
	on:
	push:
	branches:
	- master
	- main

	# This job installs dependencies, build the book, and pushes it to `gh-pages`
	jobs:
	deploy-book:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2

	# Install dependencies
	- name: Set up Python 3.7
	uses: actions/setup-python@v1
	with:
	python-version: 3.7

	- name: Install dependencies
	run: \|
	pip install -r requirements.txt


	# Build the book
	- name: Build the book
	run: \|
	jupyter-book build docs/

	# Push the book's HTML to github-pages
	- name: GitHub Pages action
	uses: peaceiris/actions-gh-pages@v3.5.9
	with:
	github_token: ${{ secrets.GITHUB_TOKEN }}
	publish_dir: ./docs/_build/html

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