linum-mode docstring is unclear

[John Shahid <jvshahid@gmail.com>]

Hey all,

I think the linum-mode docstring is unclear about when the mode is
turned on when called from Lisp. According to the docstring:

  "....  If called from Lisp, enable the mode if ARG is omitted or nil."

This isn't true. In fact, passing any value other than 0 will turn on
the mode. Furthermore, the docstring doesn't mention that passing
'toggle will toggle the state of the mode. WDYT, is that something that
can be/need clarification ?

I was thinking about borrowing the following from define-minor-mode:

  "When called from Lisp, the mode command toggles the mode if the
  argument is ‘toggle’, disables the mode if the argument is a
  non-positive integer, and enables the mode otherwise (including
  if the argument is omitted or nil or a positive integer)."

- js