utf16le encoding is missed in the File System API doc for streams #2787

There is an encoding list in the Buffer API doc: ascii, utf8, utf16le / ucs2, base64, binary, hex.

However the lists in the File System API doc for streams are not complete.

fs.createReadStream:

"The encoding can be 'utf8', 'ascii', or 'base64'."

fs.createWriteStream:

"The defaultEncoding can be 'utf8', 'ascii', binary, or 'base64'."

In the both lists the "utf16le / ucs2" encoding is misguidingly missed.