Incorrect documentation about /etc/profile

[Andras Farkas <deepbluemistake%gmail.com@localhost>]

On
https://netbsd.org/docs/misc/index.html#setting-something-for-all-users
the following text is incorrect:
> This is run every time a new shell is opened, before any .profile in the user's home directory.
/etc/profile is only read by login shells, for both sh and ksh.  This
is the actual behavior, and also the documented behavior in the man
pages.
This could probably be changed to:
> This is run every time a login shell is opened, before any .profile in the user's home directory.

I think "started" could read better than "opened", though that change
isn't as necessary.  (that could also apply to a later line about
/etc/csh.cshrc too)