v0.8.1 — README rework

v0.8.1 — README rework

A docs-only patch. No code changes.

Changed

• New "Why this exists" section — GoFastr is framed as a personal project first, with the motivations behind it: solidifying web-tech foundations, attacking UI generation from a compiled-language angle (the author's background is Node), working in a compiled language, skipping the convention-vs-configuration choice, building something large with AI, and making a framework that's AI-first on both the authoring and the consuming side.
• Removed the framework comparison from the README — the PocketBase / Encore / Wasp / Supabase / FastAPI name-drops and the comparison.md link. (The comparison.md file is left on disk for now.)
• Kiln demoted to a brief experimental mention — the ~60-line section became one paragraph linking to kiln.md, and it's no longer centerstage (dropped from "Built with GoFastr" and the install block; repo-layout line marked (experimental)).
• Migrated the README-only Kiln detail into kiln.md (plan-gated destructive ops, full tool surface, Claude Code MCP wiring, HTTP tool-call example) so nothing was lost.
• "dogfooded" → "runs on itself"; fixed the opaque "Walkthrough: the v2 read/write surface" heading → "Walkthrough: the read/write API".

Full details in CHANGELOG.md.