doc: better examples

Author: efekrskl

doc/api/net.md

@@ -1402,8 +1402,9 @@ data packet received and the first keepalive probe. Setting `0` for
 `initialDelay` will leave the value unchanged from the default
 (or previous) setting.
 
-**Note:** Node.js converts `initialDelay` from milliseconds to seconds and truncates any fractional part.
-For example, `1500` becomes `1`, and values from `1` to `999` become `0`.
+**Note**: Node.js converts initialDelay from milliseconds to seconds and truncates any fractional part.
+For example, `setKeepAlive(true, 500)` does not update the delay because it is truncated to `0`, leaving the value
+unchanged, while `setKeepAlive(true, 1500)` sets it to `1` second.
 
 Enabling the keep-alive functionality will set the following socket options: