Add a *path operation* using an HTTP PUT operation.

        ## Example

        ```python
        from fastapi import APIRouter, FastAPI
        from pydantic import BaseModel

        class Item(BaseModel):
            name: str
            description: str | None = None

        app = FastAPI()
        router = APIRouter()

        @router.put("/items/{item_id}")

                For example, if you have a model like:

                ```python
                from pydantic import BaseModel

                class Item(BaseModel):
                    name: str
                    tags: list[str] = []
                ```

                When `Item` is used for input, a request body, `tags` is not required,