fix link capitalization

Author: rtrieu

content/en/real_user_monitoring/mobile_and_tv_monitoring/ios/_index.md

@@ -23,7 +23,7 @@ To get started with RUM for iOS, create an application and configure the iOS SDK
 {{< whatsnext desc="This section includes the following topics:">}}
   {{< nextlink href="/real_user_monitoring/mobile_and_tv_monitoring/ios/setup">}}<u>Setup</u>: Learn how to set up the iOS SDK, track background events, and send data when devices are offline.{{< /nextlink >}}
   {{< nextlink href="/real_user_monitoring/mobile_and_tv_monitoring/ios/error_tracking">}}<u>Crash Reporting</u>: Add crash reporting, get deobfuscated stack traces, then test your implementation.{{< /nextlink >}}
-  {{< nextlink href="/real_user_monitoring/mobile_and_tv_monitoring/iOS/monitoring_app_performance">}}<u>Monitoring App Performance</u>: Monitor view timings to understand your app's performance from a user's perspective. {{< /nextlink >}}
+  {{< nextlink href="/real_user_monitoring/mobile_and_tv_monitoring/ios/monitoring_app_performance">}}<u>Monitoring App Performance</u>: Monitor view timings to understand your app's performance from a user's perspective. {{< /nextlink >}}
   {{< nextlink href="/real_user_monitoring/mobile_and_tv_monitoring/ios/advanced_configuration">}}<u>Advanced Configuration</u>: Enrich user sessions, manage events and data, track custom global attributes, review initialization parameters, modify or drop RUM events, and more.{{< /nextlink >}}
   {{< nextlink href="/real_user_monitoring/mobile_and_tv_monitoring/ios/mobile_vitals">}}<u>Data Collected</u>: Review data that the RUM iOS SDK collects.{{< /nextlink >}}
   {{< nextlink href="/real_user_monitoring/mobile_and_tv_monitoring/ios/mobile_vitals">}}<u>Mobile Vitals</u>: View mobile vitals, which help compute insights about your mobile application.{{< /nextlink >}}