fixing 404 link

Author: Shannon Anahata

includes/custom-measurements-supported-sdks.mdx

@@ -5,7 +5,7 @@
 - [Java (version `6.5.0` or later)](/platforms/java/performance/instrumentation/performance-metrics/)
 - [JavaScript (version `7.0.0` or later)](/platforms/javascript/performance/instrumentation/performance-metrics/)
 - [.NET (version `3.23.0` or later)](/platforms/dotnet/performance/instrumentation/performance-metrics/)
-- [Python (version `1.5.12` or later)](/platforms/python/performance/instrumentation/performance-metrics/)
+- [Python (version `1.5.12` or later)](/platforms/python/tracing/instrumentation/custom-instrumentation/)
 - [React Native (version `4.0.0` or later)](/platforms/react-native/performance/instrumentation/performance-metrics/)
 - [Ruby (version `5.8.0` or later)](/platforms/ruby/performance/instrumentation/performance-metrics/)
 - [Rails (version `5.8.0` or later)](/platforms/ruby/guides/rails/performance/instrumentation/performance-metrics/)