Fix slide refactoring and broken links - Issue #17

[jeremymanning]

This commit addresses all three requirements from Issue #17:

1. Temporal ordering of lectures (first 3 weeks):

   • Fixed Week 1: Reordered to Mon→Wed→Thu (X-hour)→Fri
   • Fixed Week 2: Reordered to Mon→Wed→Thu (X-hour)→Fri
   • Fixed Week 3: Reordered to Mon→Wed→Thu (X-hour)→Fri
   • Added X-hour demos with links to interactive notebooks

2. Automated slide compilation (PDF and HTML):

   • Updated GitHub Actions workflow to compile ALL .tex files
   • Added Jupyter notebook to HTML conversion for X-hour demos
   • Created HTML viewers for all PDF slides
   • Workflow now handles individual lecture files (lecture1.tex, etc.)
   • Supports both xelatex and pdflatex for maximum compatibility

3. Automated syllabus PDF compilation:

   • Integrated syllabus.md → syllabus.pdf compilation into workflow
   • Uses pandoc with xelatex (fallback to pdflatex)
   • Supports Berkeley Mono font when available
   • Syllabus automatically deployed to GitHub Pages

Additional improvements:

• Updated slide links in syllabus to point to specific lecture files
• Fixed all broken links to use GitHub Pages URLs
• Created comprehensive index page for all slides and X-hour materials
• Workflow triggers on changes to .tex, .ipynb, and syllabus.md files

All slides, notebooks, and syllabus will now be automatically compiled
and deployed to GitHub Pages when changes are pushed to main branch.

Closes #17