Changelog

Aug 10, 2025: Initial course material.
              Improved Figure 21 in OpenPBR course notes (no version bump).
              Minor tweaks to OpenPBR slides (no version bump).
Aug 12, 2025: Slides for EON talk.
Aug 13, 2025: Minor fixes to OpenPBR course notes (v1.1).
              Updated speaker notes and additional slide (221) for PDI presentation (no version bump).