docs: slash commands topic (#6333)

Co-authored-by: Angie Jones <jones.angie@gmail.com>

documentation/docs/guides/context-engineering/index.mdx

@@ -25,11 +25,21 @@ import styles from '@site/src/components/Card/styles.module.css';
       description="Create reusable instruction sets containing workflows, scripts, and other resources that goose can load on demand."
       link="/docs/guides/context-engineering/using-skills"
     />
+    <Card 
+      title="Custom Slash Commands"
+      description="Create custom shortcuts to quickly run reusable instructions in any chat session with simple slash commands."
+      link="/docs/guides/context-engineering/slash-commands"
+    />
     <Card 
       title="Memory Extension"
       description="Teach goose persistent knowledge it can recall across sessions. Save commands, code snippets, and preferences for consistent assistance."
       link="/docs/mcp/memory-mcp"
     />
+    <Card 
+      title="Research → Plan → Implement Pattern"
+      description="See how slash commands make it easy to integrate instructions into interactive RPI workflows."
+      link="/docs/tutorials/rpi"
+    />
   </div>
 </div>