Create archiv-fur-die-civilistische-praxis.csl

Some issues in the style guide for this journal are not implemented automatic but have to be handled manually, e.g. "Festschriften" should not mention editors (i.e. delete them manually), <strike>pages for journal article should maybe more fuzzy like "328 ff"</strike> or what a "Archivzeitschrift" is where volume is shown.
I know the editor does these and I don't think it's important enough for you to go through this again, but FYI, I try to remove attributes set to the default (such as ```font-style="normal"```) 
(I do keep them where they clarify the code, such as match="all" for if conditions)