Parallelize format builds and add consolidated publish job

[Copilot]

The single build job ran all documentation formats sequentially and inline-published to GH pages. This refactors it into parallel per-format jobs plus a dedicated publish job that runs after all builds complete. Closes #12.

Build jobs (run in parallel)

Each job installs only what it needs:

Job	Extra apt packages
build-html	—
build-text	—
build-texinfo	texinfo
build-epub	—
build-pdf	latexmk texlive-xetex fonts-freefont-otf xindy librsvg2-bin

All artifact uploads use if: always() to capture outputs (e.g. PDF logs) even on build failure.

Publish job

Runs after all five build jobs complete (needs: [build-html, build-text, build-texinfo, build-epub, build-pdf]), only when publish == 'true' and not cancelled:

publish:
  needs: [build-html, build-text, build-texinfo, build-epub, build-pdf]
  if: ${{ !cancelled() && github.event.inputs.publish == 'true' }}

Downloads all artifacts via actions/download-artifact, copies available archives into gh-pages/3/, then commits and pushes. Partial publishes (when some formats fail) are handled gracefully — missing artifacts are silently skipped.

The explicit "Check for build failures" step is removed; individual job failures surface natively in the GitHub Actions UI.

Original prompt

parallelize different format builds, add a new job after all formats finishes that will download artifacts and upload them to GH pages

The user has attached the following files from their workspace:

• .github/workflows/build.yaml

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[m-aciek]

@copilot librsvg2-bin is needed for pdf

[Copilot]

@copilot librsvg2-bin is needed for pdf

Fixed in f17d286 — moved librsvg2-bin from build-html to build-pdf.