[introspection] Add missing annotations to GDataDocumentsFolder
[introspection] Add missing annotations to GDataDocumentsFolder

Distrotech/libgdata,Distrotech/libgdata,Distrotech/libgdata,Pecisk/libgdata,Pecisk/libgdata,Pecisk/libgdata-gtasks,Pecisk/libgdata-gtasks,Pecisk/libgdata,Pecisk/libgdata-gtasks,GNOME/libgdata,pwithnall/libgdata,pwithnall/libgdata