simplify preambles to use new header #15

	name: Compile LaTeX and Upload PDFs

	on: [push]

	jobs:
	build_latex:
	runs-on: ubuntu-latest
	steps:
	- name: Set up Git repository
	uses: actions/checkout@v3
	with:
	fetch-depth: 0

	- name: Compile LaTeX documents
	uses: xu-cheng/latex-action@v2
	with:
	working_directory: "src/"
	root_file: "lec*.tex"
	glob_root_file: true

	- name: Move PDF files and commit them
	run: \|
	mv src/*.pdf .
	git config --local user.email "[email protected]"
	git config --local user.name "GitHub Action [bot]"
	git add -f "*.pdf"
	git commit -m "auto-update PDF files"

	- name: Push changes
	uses: ad-m/github-push-action@master
	with:
	github_token: ${{ secrets.GITHUB_TOKEN }}
	force: true

Provide feedback