Different kind of graph

Signed-off-by: Cliff Hill <xlorep@darkhelm.org>

README.md

@@ -49,15 +49,24 @@ graph TD
 Backend Request Data Path:
 
 ```mermaid
-graph TD
-    A[Frontend Request] -->|HTTP Request| B{FastAPI Router}
-    B -->|Matches Route| C[API Endpoint]
-    C -->|Input Validation| D[Pydantic Schema]
-    D -->|Validated Data| E[Service Layer]
-    E -->|Business Logic| F[Model]
-    F -->|DB Operations| G[Database]
-    G -->|Query Result| F
-    F -->|Processed Data| E
-    E -->|Response Data| C
-    C -->|HTTP Response| A
+sequenceDiagram
+    participant Frontend
+    participant FastAPI_Router as FastAPI Router
+    participant API_Endpoint as API Endpoint
+    participant Pydantic_Schema as Pydantic Schema
+    participant Service_Layer as Service Layer
+    participant Model
+    participant Database
+
+    Frontend->>FastAPI_Router: HTTP Request
+    FastAPI_Router->>API_Endpoint: Matches Route
+    API_Endpoint->>Pydantic_Schema: Validate Input
+    Pydantic_Schema-->>API_Endpoint: Validated Data
+    API_Endpoint->>Service_Layer: Pass Validated Data
+    Service_Layer->>Model: Apply Business Logic
+    Model->>Database: Perform DB Operations
+    Database-->>Model: Return Query Result
+    Model-->>Service_Layer: Return Processed Data
+    Service_Layer-->>API_Endpoint: Return Response Data
+    API_Endpoint-->>Frontend: HTTP Response
 ```