print unused glossary entries

This is useful if one adds a glossary entry to help the reader but doesn't want
to reference it everytime.
For example one might want to just reference acronyms and not general glossary
entries.

doku/Marketing_Ivan_Hoerler_Andreas_Zweili.tex

@@ -41,6 +41,7 @@ erarbeiteten.
 \newpage
 
 \printglossaries
+\glsaddallunused
 \end{document}