change readme.md for readable

README.md

@@ -18,22 +18,17 @@ flowchart LR
 
 
 ```mermaid
-flowchart LR
-    SDK[Python SDK] -->|logs / metrics + telemetry token| GW[Gateway]
+flowchart TD
+    SDK[Python SDK]
+    GW[Gateway<br/>Auth 鉴权<br/>Rate Limit 限流]
+    FB[Fluent Bit]
 
-    subgraph GWBox[Gateway]
-        AUTH[Auth 鉴权]
-        RL[Rate Limit 限流]
-        AUTH --> RL
-    end
-
-    GW --> AUTH
-    RL -->|logs / metrics| FB[Fluent Bit]
+    SDK -->|logs / metrics + telemetry token| GW
+    GW -->|logs / metrics| FB
 
     FB -->|logs| VLA[vlogagent]
     VLA -->|logs| VL[VictoriaLogs]
 
     FB -->|metrics| VM[VictoriaMetrics]
-
     VM -->|query| GF[Grafana]
 ```