process.stdout/.stderr/.stdin types are wrong

[nex3]

The types for Process.stdout and Process.stderr are both listed as TTYWriteStream, and the type for Process.stdin is TTYReadStream. This isn't accurate: according to the Node docs, the only consistent guarantees are that stdout and stderr are Writeables and that stdin is a Readable. In practice, they're only TTY*Streams if a terminal is attached.