Update README.md

add usage example.

Author: KoditkarVedant

README.md

@@ -19,7 +19,17 @@ dotnet add package Notion.Net
 
 ## Usage
 
-Todo
+> Before getting started, you need to [create an integration](https://www.notion.com/my-integrations) and find the token. You can learn more about authorization [here](https://developers.notion.com/docs/authorization).
+                                                                                          
+Import and initialize the client using the integration token created above.
+                                                                                          
+![image](https://user-images.githubusercontent.com/18693839/119268863-79925b00-bc12-11eb-92cb-d5a9a8c57fdc.png)
+
+Make A request to any Endpoint. For example you can call below to fetch the paginated list of users.
+                                                                                          
+![image](https://user-images.githubusercontent.com/18693839/119268924-ae9ead80-bc12-11eb-9d1a-925267896d9e.png)
+
+
 
 ## Contribution Guideline