📝 Add docs for adding example to schema (#1185)

docs_src/schema_extra_example/tutorial003.py

@@ -0,0 +1,29 @@
+from fastapi import Body, FastAPI
+from pydantic import BaseModel
+
+app = FastAPI()
+
+
+class Item(BaseModel):
+    name: str
+    description: str = None
+    price: float
+    tax: float = None
+
+
+@app.put("/items/{item_id}")
+async def update_item(
+    *,
+    item_id: int,
+    item: Item = Body(
+        ...,
+        example={
+            "name": "Foo",
+            "description": "A very nice Item",
+            "price": 35.4,
+            "tax": 3.2,
+        },
+    )
+):
+    results = {"item_id": item_id, "item": item}
+    return results