It means the spell was written in jass.
to import a jass spell, basically you need to copy the text and paste it in a trigger. The trigger you're pasting it in needs to be converted to text. To convert a trigger to text, select it and go to Edit>Convert to custom text.
Note that some spells require scripts in the mapheader. (mapheader is situated right above the first trigger in the trigger editor with the name of the map on it). You must copy the mapheader as well.
Additional note: In your jassscript you must change the raw data of the abilityId to the abilityId of the ability in your own map...