[Fontconfig] Typo in documentation

[Kang Jeong-Hee]

http://fontconfig.org/fontconfig-devel/x31.html#AEN80 and
$ grep particulat * -r
doc/fontconfig-devel.sgml:that need to reference a particulat set use one=
 of the FcSetName enumerated
doc/fontconfig-devel.txt:   run-time. Interfaces that need to reference a=
 particulat set use one of
doc/fontconfig-devel/x31.html:that need to reference a particulat set use=
 one of the FcSetName enumerated

have typo. s/particulat/particular/, right?

thx,
kz.