fix(insights/frontend): fix typo in link, backend --> frontend (#14590)

the existing link is to the backend page, but based on context it should
be to the frontend page

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## EXTRA RESOURCES

- [Sentry Docs contributor guide](https://docs.sentry.io/contributing/)

Author: uncooltoast

docs/product/insights/frontend/index.mdx

@@ -6,7 +6,7 @@ description: "Learn how to use Sentry's Frontend Performance tool to monitor thi
 
 <Include name="feature-limited-on-team-retention.mdx" />
 
-Sentry's [**Frontend Performance**](https://sentry.io/orgredirect/organizations/:orgslug/insights/backend/) page gives you an overview of the health of your application. You'll be able to see things like **Best Page Opportunities** (the improvements that would most help increase your performance score), your **Most Time-Consuming Assets**, **p50** and **p75 Duration**, and so on. 
+Sentry's [**Frontend Performance**](https://sentry.io/orgredirect/organizations/:orgslug/insights/frontend/) page gives you an overview of the health of your application. You'll be able to see things like **Best Page Opportunities** (the improvements that would most help increase your performance score), your **Most Time-Consuming Assets**, **p50** and **p75 Duration**, and so on. 
 
 ![Frontend performance overview page.](../img/frontend-performance-overview.png)