Bring the docs-site tree up to date with the richer version built on the
feature/lightning-talk line (guides, expanded reference, landing page) as the
base for adding freeroute/routing documentation. Docs-site only; no source
code from that branch is merged.
IC chip favicon eliminates the 404. Hero image shows an actual
schematic fragment (MCU, decoupling cap, LED circuit, pull-up)
so the landing page demonstrates the output, not the technology.
Scenario-driven homepage that introduces mckicad through what
engineers actually say when they sit down to work. Removes the
root redirect so / serves index.html directly.
Starlight has no index.html at document root — the landing page
lives at /getting-started/index.html. Added a 302 redirect from /
and fixed try_files to resolve directory indices correctly.
