feat: add substract with image reference

app/problems/grade_1/__init__.py

@@ -5,6 +5,9 @@ from app.problems.grade_1.join_corresponding_sums import join_corresponding_sums
 from app.problems.grade_1.join_pictures_with_quantity import (
     join_pictures_with_quantity,
 )
+from app.problems.grade_1.subtract_with_image_reference import (
+    subtract_with_image_reference,
+)
 from app.problems.grade_1.sum_with_image_reference import sum_with_image_reference
 from app.problems.grade_1.where_are_more_items import where_are_more_items
 
@@ -12,6 +15,7 @@ __all__ = [
     "compose_and_decompose_numbers",
     "join_corresponding_sums",
     "join_pictures_with_quantity",
+    "subtract_with_image_reference",
     "sum_with_image_reference",
     "where_are_more_items",
 ]