feat: add where are more items problem

ENDPOINTS-EXAMPLE.md

@@ -0,0 +1,51 @@
+# Endpoints examples
+
+Test quick examples for each endpoint:
+
+## Grade 1
+
+### Join pictures with quantity
+
+```bash
+curl -X POST "http://127.0.0.1:8000/math/grade_1/join_pictures_with_quantity" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "available_pictures": [
+      {"id": "picture-1", "name": "Apple", "image_path": "/images/apple.png"},
+      {"id": "picture-2", "name": "Banana", "image_path": "/images/banana.png"},
+      {"id": "picture-3", "name": "Car", "image_path": "/images/car.png"},
+      {"id": "picture-4", "name": "Dog", "image_path": "/images/dog.png"},
+      {"id": "picture-5", "name": "Elephant", "image_path": "/images/elephant.png"},
+      {"id": "picture-6", "name": "Fish", "image_path": "/images/fish.png"},
+      {"id": "picture-7", "name": "Grape", "image_path": "/images/grape.png"},
+      {"id": "picture-8", "name": "Hat", "image_path": "/images/hat.png"},
+      {"id": "picture-9", "name": "Ice Cream", "image_path": "/images/ice-cream.png"},
+      {"id": "picture-10", "name": "Juice", "image_path": "/images/juice.png"}
+    ],
+    "container_count_per_side": 5,
+    "min_quantity": 1,
+    "max_quantity": 10,
+    "seed": 1
+  }'
+```
+
+### Where are more items
+
+```bash
+curl -X POST "http://127.0.0.1:8000/math/grade_1/where_are_more_items" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "available_pictures": [
+      {"id": "picture-1", "name": "Panda", "image_path": "/images/panda.png"},
+      {"id": "picture-2", "name": "Koala", "image_path": "/images/koala.png"},
+      {"id": "picture-3", "name": "Orange", "image_path": "/images/orange.png"},
+      {"id": "picture-4", "name": "Apple", "image_path": "/images/apple.png"},
+      {"id": "picture-5", "name": "Donut", "image_path": "/images/donut.png"},
+      {"id": "picture-6", "name": "Candy", "image_path": "/images/candy.png"}
+    ],
+    "comparison_count": 3,
+    "min_quantity": 1,
+    "max_quantity": 10,
+    "seed": 1
+  }'
+```