Document fs.createReadStream and fs.createWriteStream close and destroy methods

[mcollina]

• Version: all
• Platform: all
• Subsystem: doc, fs, stream

As titled, those method are used in real-world code, so we should probably document them.

Related #2950.

cc @evanlucas

[mcollina]

This can be closed as it was implicitly fixed by #12925.