Yes, the Moodle version was what I updated. You can see some explanation of how it is supposed to work here
https://github.com/marcusgreen/moodle-qformat_gapfill_quick/wiki
To answer your question specifically (and from memory)
My favourite food is [chocolate!mango] {gapfill,noduplicates}
To keep it simple I have assumed a default of dragdrop.
That example might be wrong, might not work and certainly makes no sense as a question, but it might help.
And there is an examples.txt question to show how it works. However I have a more extensive example on my machine at home that should be more helpful. I may also have a later version of all the files at home, I will try to update later today (about 8 hours from now).
Here is the text of the example question from github
// EXAMPLE QUESTIONS for the Gapfill Quick import filter
// by Marcus Green Oct 2015
$CATEGORY: Gapfill2
//-----------------------------------------//
// Examples from the class description.
//-----------------------------------------//
::Q1::The [cat] sat on the [mat]. ~[hat,fat,bat,rug]
#general feedback#
#i#incorrect feedback#i#
#p#Partially correct Feedback#p#
#c#Correct Feedback #c#
{gapfill,noregex,fixedgapsize,noduplicates,casesensitive}
//This is a comment //
::QuestionName::The [cow] jumped over the [moon] #General feedback#
How now [brown] cow