Added Alphabet Letters - Slovenian ČŠŽ+ĆĐ
I added some missing letters for fulfilling the Slovenian alphabet.
I added ČŠŽ and ĆĐ for other Balkans.
Đ is made out of D because it is not present in the used font set Bitstream Vera Fonts.
Other letters here https://www.thingiverse.com/thing:15198