docs: add Starlette integration page

docs/integrations/starlette.md

@@ -0,0 +1,63 @@
+# Usage with `Starlette`
+
+Starlette has no dependency-injection system of its own, so `modern-di-starlette`
+uses the `@inject` decorator with `FromDI` markers (there is no `Depends`).
+`setup_di` composes the lifespan and installs middleware that opens a
+per-connection child container automatically.
+
+## How to use
+
+### 1. Install `modern-di-starlette`
+
+=== "uv"
+
+      ```bash
+      uv add modern-di-starlette
+      ```
+
+=== "pip"
+
+      ```bash
+      pip install modern-di-starlette
+      ```
+
+### 2. Apply to your application
+
+```python
+import dataclasses
+import typing
+
+from modern_di import Container, Group, Scope, providers
+from modern_di_starlette import FromDI, inject, setup_di
+from starlette.applications import Starlette
+from starlette.requests import Request
+from starlette.responses import JSONResponse
+from starlette.routing import Route
+
+
+@dataclasses.dataclass(kw_only=True)
+class Settings:
+    debug: bool = True
+
+
+class AppGroup(Group):
+    settings = providers.Factory(scope=Scope.APP, creator=Settings)
+
+
+@inject
+async def homepage(
+    request: Request,
+    settings: typing.Annotated[Settings, FromDI(AppGroup.settings)],
+) -> JSONResponse:
+    return JSONResponse({"debug": settings.debug})
+
+
+app = Starlette(routes=[Route("/", homepage)])
+setup_di(app, Container(groups=[AppGroup], validate=True))
+```
+
+### 3. Scopes
+
+An HTTP request opens a `Scope.REQUEST` child container; a WebSocket connection
+opens a `Scope.SESSION` one. Providers resolve from the connection's child
+container, so `Scope.REQUEST` providers live for exactly one request.

mkdocs.yml

@@ -24,6 +24,7 @@ nav:
       - FastAPI: integrations/fastapi.md
       - FastStream: integrations/faststream.md
       - Litestar: integrations/litestar.md
+      - Starlette: integrations/starlette.md
       - Typer: integrations/typer.md
       - Pytest: integrations/pytest.md
       - Writing an integration: integrations/writing-integrations.md