bug#32401: Improving set-fontset-font docstring

[Eli Zaretskii]

> From: Arun Isaac <arunisaac@systemreboot.net>
> Date: Wed, 08 Aug 2018 20:25:07 +0530
> 
> 
> There is a minor grammatical error in the following part of the
> docstring of set-fontset-font.
> 
> "TARGET may be nil.  In that case, use FONT-SPEC for any characters for
> that no FONT-SPEC is specified."
> 
> It should be "for which no FONT-SPEC is specified" instead of "for that
> no FONT-SPEC is specified". Replace "that" by "which".
> 
> Also, in an earlier part of the docstring, the description of "script
> name symbol" and "charset" could be improved by adding a link to the
> list of available scripts and charsets, or describing some means to find
> the supported scripts and charsets.

Thanks, fixed.