Fix dockerfile and add a quick test

See readme for instructions

backend/mkjam.sh

@@ -7,14 +7,18 @@ SMALL='220' # Small container (220g)
 SIZE=$LARGE
 DLUO='décembre 2023'
 LOT='0722-2'
-TENEUR='50%'
-FRUIT='80g'
-STICKER='Gelée - Cassis.svg'
+TENEUR='50' # %
+FRUIT='80' # g
+STICKER='Gelée Extra - Cassis.svg'
+DATADIR=/data
 
 PDF="`basename \"${STICKER}\" .svg` - ${LOT} (${SIZE}g).pdf"
 
-./makesticker.py --landscape --dluo "$DLUO" --lot "$LOT" --teneur "$TENEUR" --fruit "$FRUIT" --size "$SIZE" -o out.svg "$STICKER" && \
-./makeplanche.py -o pout.svg -t planche.svg.in out.svg && \
+here=$(dirname $(readlink -f $0))
+cd $DATADIR
+
+$here/makesticker.py --landscape --dluo "$DLUO" --lot "$LOT" --teneur "$TENEUR" --fruit "$FRUIT" --quantite "$SIZE" -o out.svg "$STICKER" && \
+$here/makeplanche.py -o pout.svg -t $here/planche.svg.in out.svg && \
 rm out.svg && \
 inkscape --export-type="png" --export-dpi=$DEFAULT_DPI pout.svg && \
 rm pout.svg && \