Update existing links in docstrings

fastapi/applications.py

@@ -672,7 +672,7 @@ class FastAPI(Starlette):
                 in the autogenerated OpenAPI using the `root_path`.
 
                 Read more about it in the
-                [FastAPI docs for Behind a Proxy](https://fastapi.tiangolo.com/advanced/behind-a-proxy/#disable-automatic-server-from-root_path).
+                [FastAPI docs for Behind a Proxy](https://fastapi.tiangolo.com/advanced/behind-a-proxy/#disable-automatic-server-from-root-path).
 
                 **Example**
 
@@ -739,7 +739,7 @@ class FastAPI(Starlette):
                 It will be added to the generated OpenAPI (e.g. visible at `/docs`).
 
                 Read more about it in the
-                [FastAPI docs for Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/).
+                [FastAPI docs for Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/#deprecate-a-path-operation).
                 """
             ),
         ] = None,