bug#20421: 25.0.50; doc string of `insert-buffer-substring'

[Eli Zaretskii]

> Date: Fri, 24 Apr 2015 16:19:28 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> 
> Unlike the doc string of `insert', this doc string does not explicitly
> say the following:
> 
>  Point and before-insertion markers move forward to end up
>   after the inserted text.
>  Any other markers at the point of insertion remain before the text.
> 
> It should.

Fixed.

> Here is an example where a reader did not understand some
> code, partly because, it seems, this doc string is not explicit about
> this.
> 
> http://emacs.stackexchange.com/q/10904/105

I think that reader misunderstood something else: the difference
between point and window-point.