doc: add a note about possible missing lines to readline.asyncIterator

Fixes: #33463

PR-URL: #34675
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Rich Trott <rtrott@gmail.com>

Author: mikhalev-im

doc/api/readline.md

@@ -356,6 +356,10 @@ async function processLineByLine() {
 }
 ```
 
+`readline.createInterface()` will start to consume the input stream once
+invoked. Having asynchronous operations between interface creation and
+asynchronous iteration may result in missed lines.
+
 ### `rl.line`
 <!-- YAML
 added: v0.1.98