infra: automatically post documentation previews for PRs #3


	# This workflow builds the docs for each PR (including from forks), and uploads
	# the rendered docs as an artifact.
	#
	# The artifact will be picked up by docs-preview-deploy.yml and uploaded to
	# https://jj-preview.github.io/docs/.
	#
	# The split into "build" and "deploy" follows GitHub's guide at
	# https://securitylab.github.com/resources/github-actions-preventing-pwn-requests/.
	# The build workflow has no access to the repo secrets. The deploy workflow runs
	# in the context of the main repo rather than the PR branch.

	name: docs-preview-build

	on:
	pull_request:
	paths:
	- 'docs/**'
	- 'mkdocs.yml'
	- 'pyproject.toml'
	- 'uv.lock'
	- '.github/workflows/docs-preview-build.yml'

	jobs:
	build:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683

	- name: Install uv
	uses: astral-sh/setup-uv@2e657c127d5b1635d5a8e3fa40e0ac50a5bf6992

	- name: Build the docs
	# Intentionally without --strict, to have previews even if the docs are
	# mildly broken
	run: uv run mkdocs build

	- uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882
	with:
	name: rendered-docs
	path: rendered-docs

	- run: \|
	echo ${{ github.event.pull_request.number }} > pr_number

	- uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882
	with:
	name: pr_number
	path: pr_number

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