- replace grayscale-gradient.png with svg (256 discrete rects)
- add grayscale-zoom.svg: 16 brightest shades with decimal + hex labels
- add zoom slide after '256 shades of gray'
- minor tweaks: Mbps capitalization, remove redundant '256' prefix in states list
- add cd logo, cd player, dvd, artemis images
- add artemis ii slide with apollo comparison and bandwidth calculation
- regenerate hex-dec lookup table as 16x16 grid with ascii highlight
- move hex-dec table next to hexadezimal slides
- fix mp3 bitrate: 320 -> 128 kbps to match stated file size