Trait Write is not implemented for Cursor<Vec<u8>> and Cursor<&mut Vec<u8>>

[overcat]

Currently, trait Write is not implemented for Cursor<Vec<u8>> in cursor.rs. However, the standard library includes it. Is there a specific reason why this library doesn't support it?

If possible, can we add this implementation?

impl Write for Cursor<Vec<u8>> {
    // todo
}

[overcat]

Hi @bbqsrc, if possible, I'd be happy to contribute this implementation.