bug#26925: Improve /doc/lispref/strings.texi (split-string) documentation

[Jean-Christophe Helary <jean.christophe.helary@gmail.com>]

> On 2017/06/03, at 18:59, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Jean-Christophe Helary <jean.christophe.helary@gmail.com>
>> Date: Sat, 3 Jun 2017 17:50:27 +0900
>> Cc: Eli Zaretskii <eliz@gnu.org>,
>> 26925@debbugs.gnu.org
>> 
>> -If the optional argument @var{trim}
>> →
>> +If @var{trim}
>> 
>> just to adapt the text to the description of the other arguments.
> 
> Thanks, but I see no problem with the current text.  We use both
> styles intermittently.

It's up to you. I thought it was weird that all the other optional arguments were not labeled as "optional" and only this one. And I think that comes from the fact that the trim argument was added way after the documentation was originally written and added after all the examples, so that there was no connection with the description of the other arguments.

JC