docs(GITBOOK#130): atSDK - overhaul

docs/SUMMARY.md

@@ -5,11 +5,14 @@
   * [atSign](learn/core/atsign.md)
   * [atRecord](learn/core/atrecord.md)
 * [atSDK](learn/sdk/README.md)
-  * [Onboarding](learn/sdk/onboarding.md)
+  * [Get Started](sdk/get-started.md)
+  * [Authentication](learn/sdk/onboarding.md)
   * [atKey Reference](learn/sdk/atid-reference.md)
   * [CRUD Operations](learn/sdk/crud-operations.md)
-  * [Events](learn/sdk/events.md)
-  * [Synchronization](learn/sdk/synchronization.md)
+  * [Notifications](learn/sdk/events.md)
+  * [Additional Features](sdk/synchronization/README.md)
+    * [Synchronization](sdk/synchronization/synchronization.md)
+    * [Connection Hooks](sdk/synchronization/connection-hooks.md)
 * [Infrastructure](infrastructure.md)
 
 ## 🗒️ Tutorials
@@ -22,7 +25,6 @@
   * [Send and Receive data synchronously.](tutorials/atsdk-tutorial/send-and-receive-data-synchronously.md)
   * [Remote Procedure Calls (RPC)](tutorials/atsdk-tutorial/rpc.md)
   * [atTalk - Encrypted chat client](tutorials/atsdk-tutorial/attalk.md)
-* [Starter Flutter App](tutorials/flutter-and-atsdk-app.md)
 
 ## Related pages
 

docs/learn/sdk/README.md

@@ -2,10 +2,8 @@
 
 ## Overview
 
-An atClient is any client application which uses the atProtocol to interact with an atServer. This can be anything from a desktop application to a small background service running on a microcontroller.
-
-The atClient SDKs provide everything you need to write an application which implements the atProtocol. This SDK reference is generic and has been broken up into sections to show the basic principles, to get coding take a look at the [tutorials](broken-reference).
+The atSDK is the best way to embed the atProtocol into new or existing software. This can be anything from a graphical desktop application to firmware flashed on a microcontroller.
 
 ### Sections
 
-<table data-column-title-hidden data-view="cards"><thead><tr><th data-card-target data-type="content-ref">Link</th><th>Description</th></tr></thead><tbody><tr><td><a href="onboarding.md">onboarding.md</a></td><td>How to authenticate an atClient to an atServer</td></tr><tr><td><a href="atid-reference.md">atid-reference.md</a></td><td>Learn how to create atKeys for your chosen platform</td></tr><tr><td><a href="crud-operations.md">crud-operations.md</a></td><td>How to do basic CRUD operations on an atServer</td></tr><tr><td><a href="events.md">events.md</a></td><td>How to send and receive real-time events</td></tr><tr><td><a href="synchronization.md">synchronization.md</a></td><td>How to sync and persist data with an atServer</td></tr></tbody></table>
+<table data-column-title-hidden data-view="cards"><thead><tr><th data-card-target data-type="content-ref">Link</th><th>Description</th></tr></thead><tbody><tr><td><a href="../../sdk/get-started.md">get-started.md</a></td><td>Setup the atSDK for your preferred language</td></tr><tr><td><a href="onboarding.md">onboarding.md</a></td><td>How to authenticate to an atServer</td></tr><tr><td><a href="atid-reference.md">atid-reference.md</a></td><td>Learn how to create atKeys for your chosen platform</td></tr><tr><td><a href="crud-operations.md">crud-operations.md</a></td><td>How to do basic CRUD operations on an atServer</td></tr><tr><td><a href="events.md">events.md</a></td><td>How to send and receive real-time messages</td></tr><tr><td><a href="../../sdk/synchronization/">synchronization</a></td><td>Implementation specific features to know about</td></tr></tbody></table>