Add a dummy cron job to create PRs/issues/zulip-threads #13

	name: Continuous Integration

	on:
	push:
	branches:
	- master
	pull_request:

	jobs:
	book-test:
	runs-on: ubuntu-22.04
	steps:
	- uses: actions/checkout@v3
	with:
	fetch-depth: 0

	- name: Install mdbook
	run: \|
	cargo install --version "^0.4.5" mdbook
	cargo install --version "^1.3.1" skill-tree

	- name: mdbook test
	run: \|
	mdbook build
	mdbook test

	- name: check skill-tree
	run: skill-tree roadmap.toml book/roadmap

	- name: Deploy GitHub Pages
	if: github.ref == 'refs/heads/master'
	run: \|
	git worktree add gh-pages gh-pages
	git config user.name "Deploy from CI"
	git config user.email ""
	cd gh-pages
	# Delete the ref to avoid keeping history.
	git update-ref -d refs/heads/gh-pages
	rm -rf *
	mv ../book/* .
	git add .
	git commit -m "Deploy $GITHUB_SHA to gh-pages"
	git push --force

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