style: format code with Gofumpt and Prettier

This commit fixes the style issues introduced in d7736ce according to the output
from Gofumpt and Prettier.

Details: #2491

docs/tutorial/get-started.md

@@ -443,8 +443,8 @@ If you are interested, please refer to [SDKs](../user-guides/sdks.md).<br>
           ```go
           _, err := client.Flush(ctx, &payload.Flush_Request{})
           if err != nil {
-		            glg.Fatal(err)
-		        }
+                    glg.Fatal(err)
+                }
           ```
 
             </details>