bluetooth: README files updated to improve cross-linking.

third_party/WebKit/Source/modules/bluetooth/README.md

-Web Bluetooth
-=============
+# Web Bluetooth Blink Module
 
-`Source/modules/bluetooth` implements [Web Bluetooth][WB].
+`Source/modules/bluetooth` implements the renderer process details and bindings
+for the [Web Bluetooth specification]. It uses the Web Bluetooth Service
+[mojom] to communicate with the [Web Bluetooth Service].
 
-[WB]: https://webbluetoothcg.github.io/web-bluetooth/
+[Web Bluetooth specification]: https://webbluetoothcg.github.io/web-bluetooth/
+[mojom]: ../../../public/platform/modules/bluetooth/web_bluetooth.mojom
+[Web Bluetooth Service]: /content/browser/bluetooth/
 
-Scanning
---------------------------------------------------------------------------------
+
+## LE only Scanning
+
 There isn't much support for GATT over BR/EDR from neither platforms nor
 devices so performing a Dual scan will find devices that the API is not
 able to interact with. To avoid wasting power and confusing users with
 devices they are not able to interact with, navigator.bluetooth.requestDevice
 performs an LE-only Scan.
 
-Testing
---------------------------------------------------------------------------------
+
+## Testing
 
 Bluetooth layout tests in `LayoutTests/bluetooth/` rely on
 fake Bluetooth implementation classes constructed in
 `content/shell/browser/layout_test/layout_test_bluetooth_adapter_provider`.
 These tests span JavaScript binding to the `device/bluetooth` API layer.
 
+See also the [Web Bluetooth Fuzzer](testing/clusterfuzz/README.md).
 
-Design Documents
---------------------------------------------------------------------------------
+
+## Design Documents
 
 See: [Class Diagram of Web Bluetooth through Bluetooth Android][Class]
 
 [Class]: https://sites.google.com/a/chromium.org/dev/developers/design-documents/bluetooth-design-docs/web-bluetooth-through-bluetooth-android-class-diagram