README: frame it explicitly as the single entry point with by-goal routing

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -5,10 +5,18 @@ A minimal, purpose-built writing interface for the **reMarkable Paper Pro Move**
 conversation partner reads. Chatter *augments* the stock reMarkable software; it
 does not replace it.
 
-- **End-user instructions:** [`doc/Chatter_user_guide.md`](doc/Chatter_user_guide.md)
-- **Full technical reference (developers start here):**
+**Start here.** This README is the entry point — it takes you from a clone to
+Chatter running on a tablet, and everything else you might need is one of these
+links. You should not need any information that isn't in this repository.
+
+- **Install / test it on a tablet** → keep reading (**Quick install**, below).
+- **What the user sees and how she uses it** →
+  [`doc/Chatter_user_guide.md`](doc/Chatter_user_guide.md)
+- **How it works, or to modify the code** →
   [`doc/Chatter_technical_reference.md`](doc/Chatter_technical_reference.md)
-- **Plan & history:** [`doc/Chatter_implementation.md`](doc/Chatter_implementation.md)
+  — the complete master document; it links every other doc.
+- **Project plan & history** →
+  [`doc/Chatter_implementation.md`](doc/Chatter_implementation.md)
 
 ## Repository layout