Add tip about Bob the Agent Builder

Author: jahooma

web/src/content/walkthroughs/creating-your-first-agent.mdx

@@ -111,6 +111,8 @@ Your job is to review code changes and provide helpful, constructive feedback.`,
 export default definition
 ```
 
+**💡 Quick tip:** You can also invoke `@Bob the Agent Builder` inside Codebuff to help you build an agent. However, we recommend trying to build your first agent manually to understand the fundamentals.
+
 ## Step 3: Test Your Agent Locally
 
 Now test your agent with Codebuff: