revert performance API docs while we fix exports (#7766)

Author: AbhiPrasad

src/platforms/common/performance/instrumentation/custom-instrumentation.mdx

@@ -37,15 +37,15 @@ To capture transactions and spans customized to your organization's needs, you m
 
 </Note>
 
-<PlatformSection notSupported={["javascript", "node"]}>
+<PlatformSection notSupported={[" "]}>
 
 <PlatformContent includePath="performance/enable-manual-instrumentation" />
 
 <PlatformContent includePath="performance/add-spans-example" />
 
 </PlatformSection>
 
-<PlatformSection supported={["javascript", "node"]}>
+<PlatformSection supported={[" "]}>
 
 To add custom performance data to your application, you need to add custom instrumentation in the form of spans. Spans are a way to measure the time it takes for a specific action to occur. For example, you can create a span to measure the time it takes for a function to execute.
 
@@ -97,7 +97,7 @@ Sentry maintains a [list of well known span operations](https://develop.sentry.d
 
 </PlatformSection>
 
-<PlatformSection notSupported={["java", "native", "apple", "javascript", "node"]}>
+<PlatformSection notSupported={["java", "native", "apple"]}>
 
 <PlatformContent includePath="performance/retrieve-transaction" />