Fix typo

Author: sis0k0

docs/75-optimize/3-optimize.mdx

@@ -34,9 +34,9 @@ How many calls do you need to do to your database now? Do you still need an aggr
 </TabItem>
 
 <TabItem value="java" label="☕️ Java Spring Boot">
-1. Open the `BookService` class
+1. Open the `BookService` class - `java-server/src/main/java/com/mongodb/devrel/library/domain/service/BookService.java`.
 
-2. locate the `getBook` method.
+2. Locate the `getBook` method.
 
 How could you simplify this code to make it blazing fast, using the patterns we just discussed?