docs: cleaner README hero, strip em dashes, tighten copy

- Replace garbled ASCII-block hero with a clean centered H1 + subtitle
- Drop every em dash from prose. Plain periods and commas where the dashes were doing theatrical work
- Quote-block TL;DR so the pitch reads as a callout instead of body text
- Drop the awkward "drop GIF here" placeholder shield
- Shorter Why-star-this section, tighter comparison table, cleaner repo-layout tree
- Straight sentences only. No --, no long dashes, no stacked clauses

Author: Devansh-365