📝 Update docs, add first tutorials

docs/tutorial/src/all/tutorial018.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
+
+
+class User(BaseModel):
+    username: str
+    full_name: str = None
+
+
+@app.put("/items/{item_id}")
+async def update_item(
+    *, item_id: int, item: Item, user: User, access_token: str = Body(...)
+):
+    results = {
+        "item_id": item_id,
+        "item": item,
+        "user": user,
+        "access_token": access_token,
+    }
+    return results