Revert change to MySql README

src/OpenTelemetry.Instrumentation.MySqlData/README.md

@@ -101,6 +101,26 @@ using var tracerProvider = Sdk.CreateTracerProviderBuilder()
     .Build();
 ```
 
+## EnableConnectionLevelAttributes
+
+By default, `EnabledConnectionLevelAttributes` is disabled and this
+instrumentation sets the `peer.service` attribute to the
+[`DataSource`](https://docs.microsoft.com/dotnet/api/system.data.common.dbconnection.datasource)
+property of the connection. If `EnabledConnectionLevelAttributes` is enabled,
+the `DataSource` will be parsed and the server name will be sent as the
+`net.peer.name` or `net.peer.ip` attribute, and the port will be sent as the
+`net.peer.port` attribute.
+
+The following example shows how to use `EnableConnectionLevelAttributes`.
+
+```csharp
+using var tracerProvider = Sdk.CreateTracerProviderBuilder()
+    .AddMySqlDataInstrumentation(
+        options => options.EnableConnectionLevelAttributes = true)
+    .AddConsoleExporter()
+    .Build();
+```
+
 ### RecordException
 
 This option can be set to instruct the instrumentation to record Exceptions