Add StaticFile and StaticFiles to README

README.md

@@ -172,6 +172,8 @@ Takes a different set of arguments to instantiate than the other response types:
 * `media_type` - A string giving the media type. If unset, the filename or path will be used to infer a media type.
 * `filename` - If set, this will be included in the response `Content-Disposition`.
 
+File responses will include appropriate `Content-Length`, `Last-Modified` and `ETag` headers.
+
 ```python
 from starlette import FileResponse
 
@@ -278,12 +280,12 @@ dispatches to other ASGI applications.
 
 ```python
 from starlette import Router, Path, PathPrefix
-from myproject import Homepage, StaticFiles
+from myproject import Homepage, SubMountedApp
 
 
 app = Router([
     Path('/', app=Homepage, methods=['GET']),
-    PathPrefix('/static', app=StaticFiles, methods=['GET'])
+    PathPrefix('/mount/', app=SubMountedApp)
 ])
 ```
 
@@ -313,6 +315,30 @@ responses for requests which do not match.
 
 ---
 
+## Static files
+
+As well as the `FileResponse` class, Starlette also includes ASGI applications
+for serving a specific file or directory:
+
+* `StaticFile(path)` - Serve a single file, given by `path`.
+* `StaticFiles(directory)` - Serve any files in the given directory.
+
+You can combine these ASGI applications with Starlette's routing to provide
+comprehensive static file serving.
+
+```python
+from starlette.routing import Router, Path, PathPrefix
+from starlette.staticfiles import StaticFile, StaticFiles
+
+
+app = Router(routes=[
+    Path('/', app=StaticFile('index.html')),
+    PathPrefix('/static/', app=StaticFiles(directory='static')),
+])
+```
+
+---
+
 ## Test Client
 
 The test client allows you to make requests against your ASGI application,