Merge pull request modelcontextprotocol#164 from modelcontextprotocol/zack-lee/fix-diagram

fixed mermaid diagram in /architecture

Author: zckly

docs/concepts/architecture.mdx

@@ -15,7 +15,7 @@ MCP follows a client-server architecture where:
 
 ```mermaid
 flowchart LR
-    subgraph " Host (e.g., Claude Desktop) "
+    subgraph " Host "
         client1[MCP Client]
         client2[MCP Client]
     end