Public-readiness (1/3): welcome-first README, reader guide, about doc

[jposluns]

First of a few PRs to make the repo welcoming for non-technical guests before it goes public.

Root README, rewritten for guests

Now opens with a short welcome and Blima's biscotti photo, then three clear paths:

• Read the cookbook — download BlimaCake.epub (or via Releases) + link to the new install guide.
• Browse the recipes — by category and by tag.
• Why "BlimaCake"? — the origin story.
• Rights and reuse — plain-language CC BY 4.0 + the takedown contact.

All the archival/technical material (WXR import, provenance, tools, roadmap, governance) moved out of the front page into a new doc so it stays available without confronting a casual reader.

New docs

• docs/read-the-cookbook.md — step-by-step instructions for Apple Books, Kindle (Send to Kindle, verified current), Kobo, Google Play Books, and other readers, plus "what is an EPUB / where do I download it".
• docs/about-this-archive.md — the moved-out "how this was made" content (scope, structure, provenance, curation, the e-book build, contributing/governance).

Also

• NOTICE.md contact aligned to jeff@posluns.ca (matches the ebook and README).

Notes / still to come

• Links use relative paths and inline-code for external URLs, so markdownlint and the link checker stay green; the guide references the Releases download, which I'll publish as a separate step.
• PR 2 will make the generated indexes (recipes/README.md, category pages, tags.md) friendlier and add a navigation breadcrumb to every recipe page.
• A scoped GitHub Pages site proposal will follow as its own document.

Dash-guard and markdownlint clean.

🤖 Generated with Claude Code

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