Update Claude Agent SDK documentation link

Author: quicksandznzn

README.md

@@ -1,6 +1,6 @@
 # Claude Agent SDK for Python
 
-Python SDK for Claude Agent. See the [Claude Agent SDK documentation](https://docs.anthropic.com/en/docs/claude-code/sdk/sdk-python) for more information.
+Python SDK for Claude Agent. See the [Claude Agent SDK documentation](https://platform.claude.com/docs/en/agent-sdk/python) for more information.
 
 ## Installation