Added "timeouts" as one type of events users should handle as part of their use of Pipeline.

Database/MongoDB/Internal/Protocol.hs

@@ -196,7 +196,7 @@ pcall p@Pipeline{..} message = do
 
 type Pipe = Pipeline
 -- ^ Thread-safe TCP connection with pipelined requests. In long-running applications the user is expected to use it as a "client": create a `Pipe` 
--- at startup, use it as long as possible, and close it on shutdown. Bearing in mind that disconnections may be triggered by MongoDB service providers, the user is responsible for re-creating their `Pipe` whenever necessary. 
+-- at startup, use it as long as possible, watch out for possible timeouts, and close it on shutdown. Bearing in mind that disconnections may be triggered by MongoDB service providers, the user is responsible for re-creating their `Pipe` whenever necessary. 
 
 newPipe :: ServerData -> Handle -> IO Pipe
 -- ^ Create pipe over handle