docs: refine static reading experience

docs/src/SUMMARY.md

@@ -1,13 +1,28 @@
 # Summary
 
-- [Kaptan documentation](index.md)
+- [Overview](index.md)
+
+# Start here
+
 - [Getting started](getting-started.md)
+- [Development and verification](development.md)
+
+# Design
+
 - [Architecture](architecture.md)
   - [Safety boundary](safety-boundary.md)
   - [MAVLink and telemetry](mavlink.md)
+
+# Platforms
+
 - [Boards](boards/index.md)
   - [Kakute F7 Mini V3](boards/kakute-f7-mini-v3.md)
   - [GEPRC GEP-F722-HD V2](boards/geprc-f722-v2.md)
+
+# Simulation
+
 - [Host SITL](sitl.md)
-- [Development and verification](development.md)
+
+# Reference
+
 - [Reference](reference.md)

docs/src/index.md

@@ -1,13 +1,13 @@
-# Kaptan documentation
+# Overview
 
 Kaptan is an embedded Rust flight-controller project. This manual is the
 single source of project documentation: board support, safety boundaries,
 simulation, development workflow, and design references live here as
 Markdown.
 
-The checked-in firmware is telemetry-only. It does not expose physical motor
-authority, and no document in this site should be read as a physical-flight
-release claim.
+> **Status:** the checked-in firmware is telemetry-only. It does not expose
+> physical motor authority, and this site does not make a physical-flight
+> release claim.
 
 ## Index