Document canonical Caddy migration

docs/index.md

@@ -158,6 +158,10 @@ The LLM inference fleet on the two hosts. Full index:
 - [[Sample Script Set]] — reference scripts for the PP pair
 - [[vLLM Pipeline Parallelism]] — vLLM's PP implementation
 
+## Update Log
+
+- [[log]] — chronological record of knowledge-base changes
+
 ## See Also
 
 - [AGENTS.md](../AGENTS.md) — repository rules