Update README.md

Author: jessicayzhao

README.md

@@ -18,7 +18,7 @@ Run `npm install` in the root directory to install all dependencies for the `cli
 The schemas for the database are documented in the directory `server/models/schema`.
 A class diagram for the schema definition is shown below:
 
-![Class Diagram](class-diagram.png)
+![Class Diagram](new-class-diagram.png)
 
 ## API Routes
 
@@ -132,6 +132,15 @@ A class diagram for the schema definition is shown below:
 | /updateGamerInfo  | PATCH  | Updates gamer information      |
 | /getLeaderboard   | GET    | Gets gamer leaderboard         |
 
+### `/star`
+
+| Endpoint    | Method  | Description                   |
+| ----------- | ------- | ----------------------------- |
+| /getStars   | GET     | Get a user's stars            |
+| /addStar    | POST    | Add a star to a question      |
+| /removeStar | DELETE  | Remove a star from a question |
+
+
 ## Running Stryker Mutation Testing
 
 Mutation testing helps you measure the effectiveness of your tests by introducing small changes (mutations) to your code and checking if your tests catch them. To run mutation testing with Stryker, use the following command in `server/`: