Replace flat 15-row table with a Before/After ASCII diagram plus a
capability grid (Search/Graph/Filter/VFS/Branch/Import) with competitors
grouped by category. Add new What Can You Build? section with generic
use cases and Built with Brainy showcase. Tighten header copy.
Adds docs/eli5.md — a jargon-free explanation of Brainy and Cortex
using everyday analogies (smart librarian, turbocharger). Targets
non-technical readers who want to understand the project before diving
into the API. Links added at the top of README and in the Documentation
section index.
