Updated the "Definition of formatting functions" section to include a description of the new "IFDEFP" function and a link to the description of the "DEFP" function.
Updated the "Definition of formatting functions" section to include a description
of the new "IFDEFP" function and a link to the description of the "DEFP" function.

tiborsimko/invenio,inveniosoftware/invenio,inveniosoftware/invenio,tiborsimko/invenio