Contradiction in Readable docs

[reergymerej]

The readable.push() method is intended be called only by Readable implementers, and only from within the readable._read() method.

This immediately follows an example showing

if (!this.push(chunk))
        this._source.readStop();

in the constructor instead.

[ImHype]

Could we add some suggested descriptions to the document?

[lpinca]

Fixed by #29687.