docs: update the screenshot of sandbox for potential confusion (#7869)

Author: xupea

docs/source/getting-started.mdx

@@ -288,7 +288,7 @@ We can now execute GraphQL queries on our server. To execute our first query, we
 
 Visit `http://localhost:4000` in your browser, which will open the Apollo Sandbox:
 
-<img class="screenshot" src="./images/sandbox.jpeg" alt="Apollo Sandbox" />
+<img class="screenshot" src="./images/default-sandbox.jpg" alt="Default Apollo Sandbox" />
 
 The Sandbox UI includes: