add while loop information

doc/api/stream.md

@@ -1556,12 +1556,15 @@ readable.on('end', () => {
 ```
 
 Each call to `readable.read()` returns a chunk of data or `null`, signifying
-that there's no more data to read. These chunks aren't automatically concatenated.
+that there's no more data to read at that moment. These chunks aren't automatically
+concatenated. Because a single `read()` call does not return all the data, using
+a while loop may be necessary to continuously read chunks until all data is retrieved.
+When reading a large file, `.read()` might return `null` temporarily, indicating
+that it has consumed all buffered content but there may be more data yet to be
+buffered. In such cases, a new `'readable'` event is emitted once there's more
+data in the buffer, and the `'end'` event signifies the end of data transmission.
 Typically, you'd use event listeners, such as `'data'` and `'end'`, to handle the
-stream's data. When reading a large file, `.read()` might return `null` temporarily,
-indicating that it has consumed all buffered content but there may be more data yet to
-be buffered. In such cases, a new `'readable'` event is emitted once there's more data
-in the buffer, and the `'end'` event signifies the end of data transmission.
+stream's data.
 
 Therefore to read a file's whole contents from a `readable`, it is necessary
 to collect chunks across multiple `'readable'` events: