General aviation pilot reported taxiing past a hold short line into a runway approach path area at GNV which was not depicted on their charts.

Narrative

It was my first time in to and out of GNV. I stopped for a quick gas and go enroute to final destination of ZZZ. I received my IFR clearance from Ground Control and after read back was given taxi instructions to Runway 7. I requested departure from Runway 11 and was given a taxi clearance to 11; but to hold short of Runway 7. After the read back; I was given clarification to hold short of the approach path of Runway 11. The taxi from the ramp was fairly quick and I was heads down looking at my taxi chart to ensure I didn't cross Runway 7. There was another GA aircraft taxiing in front of me and I saw him hold short of 7 and confirmed on my chart the appropriate route. However; I mistook the instructions from the Ground Controller and passed the approach area of Runway 11 while I stopped short of Runway 7 behind the aircraft ahead. Ground Control asked me if I passed the hold short line for runway 11. I immediately thought I had crossed Runway 7; but was the advised I had passed the approach path of 11. I was definitely confused and brought the aircraft to an immediate stop and asked for clarification. Ground Control told me to continue to hold short of Runway 7 and to contact Tower for further clearance to Runway 11. I looked on the taxi chart both in Foreflight and on my Jepps; I saw no indication on the chart showing any depiction of a hold short of the approach path to Runway 11. I apologized for the error and Ground Control confirmed his previous instructions.In the future; I definitely learned that if I'm not certain of a taxi clearance; then it is incumbent upon me to seek clarification from Ground Control. I think the taxi chart could be amended to highlight the exact spot Ground expects crews to stop and hold short of the approach path of Runway 11. I hope others can learn from my experience.