Add `cei:index` to `cei:persName`
Created by: GVogeler
schema allows already cei:placeName/cei:index
to encode terms like "castle", "church", "chapel" as part of place name. Does this fit to cei:persName
too? TEI allows term
in persName
as well (http://www.tei-c.org/release/doc/tei-p5-doc/en/html/ref-term.html).