Correct place to put the new doc for "How to use this driver"

[rishi gupta]

Hi Team,

I need to add a documentation file to let users know "how to use this driver".
Specifically this one (tty-ttyvs.rst): https://lkml.org/lkml/2020/2/15/153

(1) I am unable to find any directory where it will fit. This driver
belongs to Virtual TTY device category.
Any suggestions where to put it?

(2) After putting it is it mandatory to link it to
Documentation/index.rst as suggested here
https://www.kernel.org/doc/html/latest/doc-guide/index.html

Regards,
Rishi