[docs] List supported processor architecture in Compatibility section (…

…#3016)

docs/README.md

@@ -81,6 +81,15 @@ The minimal supported version of
 [.NET Framework](https://dotnet.microsoft.com/download/dotnet-framework)
 is `4.6.2`.
 
+Supported processor architectures are:
+
+- x86
+- AMD64 (x86-64)
+
+> **Note**
+> ARM architectures are not supported yet,
+> see [#2181](https://github.com/open-telemetry/opentelemetry-dotnet-instrumentation/issues/2181).
+
 CI tests run against the following operating systems:
 
 - [Alpine](https://github.com/open-telemetry/opentelemetry-dotnet-instrumentation/blob/main/docker/alpine.dockerfile)
@@ -95,10 +104,6 @@ See [config.md#instrumented-libraries-and-frameworks](config.md#instrumented-lib
 
 ## Get started
 
-> **Note**
-> ARM architectures are not supported yet,
-> see [#2181](https://github.com/open-telemetry/opentelemetry-dotnet-instrumentation/issues/2181).
-
 ### Considerations on scope
 
 Instrumenting [`self-contained`](https://learn.microsoft.com/en-us/dotnet/core/deploying/#publish-self-contained)