Update README.md (#124)

Author: m-xim

README.md

@@ -84,7 +84,7 @@ class MyAPIClient(RequestsWebClient):
     def create_user(self, user: CreateUser) -> UserResponse:
         pass
 
-    @get("/users/string?name={name})
+    @get("/users/string?name={name}")
     def get_user_string(self, name: Optional[str] = None) -> dict:
         # will get raw json data
         ...
@@ -154,7 +154,7 @@ def get_user_post(self, user_id: int, post_id: int) -> PostResponse:
 
 ```python
 
-# you can cal signature by your self, overwrite the function `before_request`
+# you can call signature by your self, overwrite the function `before_request`
 from pydantic_client.schema import RequestInfo
 
 
@@ -164,7 +164,7 @@ class MyAPIClient(RequestsWebClient):
     def before_request(self, request_params: Dict[str, Any]) -> Dict[str, Any]:
         # the request params before send: body, header, etc...
         sign = cal_signature(request_params)
-        request_params["headers].update(dict(signature=sign))
+        request_params["headers"].update(dict(signature=sign))
         return request_params