Update FastMCP server documentation link (#2529)

The link to FastMCP Server Documentation was pointing to /servers/fastmcp which returns 404. Changed to /servers/server.

Co-authored-by: Jeremiah Lowin <[email protected]>

Author: sskim91

README.md

@@ -160,7 +160,7 @@ from fastmcp import FastMCP
 mcp = FastMCP(name="MyAssistantServer")
 ```
 
-Learn more in the [**FastMCP Server Documentation**](https://gofastmcp.com/servers/fastmcp).
+Learn more in the [**FastMCP Server Documentation**](https://gofastmcp.com/servers/server).
 
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