Docs: primary slides PDF link

Author: ShuhaoZhangTony

.github/workflows/slides-pages.yml

@@ -0,0 +1,19 @@
+name: Slides (disabled)
+
+on:
+  workflow_dispatch:
+
+# No automatic triggers.
+
+# This workflow is intentionally disabled.
+# The slides source repository is private, and this public repo should not store a token to access it.
+# Publishing is done from the private slides repo by pushing a built PDF to this repo's `gh-pages` branch.
+
+jobs:
+  disabled:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Disabled
+        run: |
+          echo "This workflow is disabled."
+          echo "Slides are published by the private slides repository pushing to the gh-pages branch of this repo."

README.md

@@ -24,3 +24,6 @@ chmod +x setup.sh
 ## Relation to slides
 
 The lecture slides live in a separate repository (PDF + LaTeX). This repo is intended to be **public** so students can browse and run the code.
+
+- Primary slides PDF (GitHub Pages): [https://intellistream.github.io/parallel-computing-course-java-demos/main.pdf](https://intellistream.github.io/parallel-computing-course-java-demos/main.pdf)
+- Slides source repo (may be private): [https://github.com/intellistream/parallel-computing-course-java](https://github.com/intellistream/parallel-computing-course-java)