Create medienwandel-medienwechsel-medienwissen-chronos.csl

Style for Medienwandel – Medienwechsel – Medienwissen created.
why not do 
```
<choose>
<if variable="page">
<choose>
<if type="chapter article-journal article-magazine article-newspaper" match="any">
<text prefix=", hier " macro="citation-locator"/>
</if>
</choose>
</if>
<else>
<text prefix=", " macro="citation-locator"/>
</else>
</choose>