Update docs for README

Summary:
- Docs: update docs for README
- Assets: add Assets

Stats:
- 2 files changed, 36 insertions(+)

README.md

@@ -15,6 +15,42 @@ StorageRouter (main entry point)
     └── SyncHelper
 ```
 
+![LocalData Architecture](Assets/architecture_diagram.png)
+
+```mermaid
+graph TD
+    App[App / Feature] -->|StorageKey| SR[StorageRouter]
+    
+    subgraph Config [Global Configuration]
+        SC[StorageConfiguration]
+        EC[EncryptionConfiguration]
+        FC[FileStorageConfiguration]
+        SYC[SyncConfiguration]
+    end
+    
+    SR -.->|Resolves Defaults| Config
+    
+    SR -->|Delegates| KH[KeychainHelper]
+    SR -->|Delegates| FH[FileStorageHelper]
+    SR -->|Delegates| UH[UserDefaultsHelper]
+    
+    KH --- EH[EncryptionHelper]
+    FH --- EH
+    
+    SR -->|Syncs| SH[SyncHelper]
+    
+    subgraph Storage [Hardware Storage]
+        KC[(Keychain)]
+        FS[(File System)]
+        UD[(UserDefaults)]
+    end
+    
+    KH --> KC
+    FH --> FS
+    UH --> UD
+    SH -->|WatchConnectivity| WatchOS[Apple Watch]
+```
+
 ## What Ships in the Package
 
 ### Protocols