doc: update socket.remote* properties documentation

Fixes: #48061
PR-URL: #48139
Reviewed-By: Ben Noordhuis <[email protected]>
Reviewed-By: Paolo Insogna <[email protected]>
Reviewed-By: Rich Trott <[email protected]>

Author: Basa198

doc/api/net.md

@@ -1136,7 +1136,8 @@ added: v0.11.14
 
 * {string}
 
-The string representation of the remote IP family. `'IPv4'` or `'IPv6'`.
+The string representation of the remote IP family. `'IPv4'` or `'IPv6'`. Value may be `undefined` if
+the socket is destroyed (for example, if the client disconnected).
 
 ### `socket.remotePort`
 
@@ -1146,7 +1147,8 @@ added: v0.5.10
 
 * {integer}
 
-The numeric representation of the remote port. For example, `80` or `21`.
+The numeric representation of the remote port. For example, `80` or `21`. Value may be `undefined` if
+the socket is destroyed (for example, if the client disconnected).
 
 ### `socket.resetAndDestroy()`