fix: speed brain enable/disable typo (#17009)

Author: Cherry

src/content/docs/speed/optimization/content/speed-brain.mdx

@@ -75,7 +75,7 @@ Speed Brain is available in Cloudflare's **Speed** tab of the dashboard and also
 
 <Tabs syncKey="dashPlusAPI"> <TabItem label="Dashboard">
 
-To enable or disable **Prefetch URLs** in the dashboard:
+To enable or disable **Speed Brain** in the dashboard:
 
 1. Log in to your [Cloudflare account](https://dash.cloudflare.com), select your account and go to a specific domain.
 2. Go to **Speed** > **Optimization** > **Content Optimization**.