Updates the Unity SDK docs with new SetData methods on spans & transa…

docs/platforms/unity/tracing/instrumentation/custom-instrumentation.mdx

@@ -15,3 +15,5 @@ To capture transactions and spans customized to your organization's needs, you m
 <PlatformContent includePath="performance/add-spans-example" />
 
 <PlatformContent includePath="performance/retrieve-transaction" />
+
+<PlatformContent includePath="performance/improving-data" /> 

platform-includes/configuration/data-to-all-spans/unity.mdx

@@ -0,0 +1,22 @@
+```csharp
+SentrySdk.Init(options =>
+{
+    options.SetBeforeSendTransaction(transaction =>
+    {        
+        // Set the attribute on the root span
+        if (transaction.Contexts.Trace == null)
+        {
+            transaction.Contexts.Trace = new SpanContext();
+        }
+        transaction.Contexts.Trace.SetData("myAttribute", "myValue");
+
+        // And on all child spans
+        foreach (var span in transaction.Spans)
+        {
+            span.SetData("myAttribute", "myValue");
+        }
+
+        return transaction;
+    });
+});
+``` 

platform-includes/performance/improving-data/unity.mdx

@@ -0,0 +1,47 @@
+## Improving Data on Transactions and Spans
+
+### Adding Data Attributes to Transactions
+
+You can add data attributes to your transactions. This data is visible in the trace explorer in Sentry. Data attributes can be of type `string`, `number` or `boolean`, as well as arrays of these types:
+
+```csharp
+ITransaction transaction = SentrySdk.StartTransaction("processOrderBatch()", "task");
+transaction.SetData("my-data-attribute-1", "value1");
+transaction.SetData("my-data-attribute-2", 42);
+transaction.SetData("my-data-attribute-3", true);
+
+transaction.SetData("my-data-attribute-4", new[] {"value1", "value2", "value3"});
+transaction.SetData("my-data-attribute-5", new[] {42, 43, 44});
+transaction.SetData("my-data-attribute-6", new[] {true, false, true});
+```
+
+<Alert level="info">
+The <code>SetExtra</code> method is still supported but has been deprecated in favor of <code>SetData</code>.
+</Alert>
+
+### Adding Data Attributes to Spans
+
+You can add data attributes to your spans. This data is visible in the trace explorer in Sentry. Data attributes can be of type `string`, `number` or `boolean`, as well as arrays of these types:
+
+```csharp
+ISpan span = parent.StartChild("task", "operation");
+span.SetData("my-data-attribute-1", "value1");
+span.SetData("my-data-attribute-2", 42);
+span.SetData("my-data-attribute-3", true);
+
+span.SetData("my-data-attribute-4", new[] {"value1", "value2", "value3"});
+span.SetData("my-data-attribute-5", new[] {42, 43, 44});
+span.SetData("my-data-attribute-6", new[] {true, false, true});
+```
+
+### Adding Attributes to all Spans and Transactions
+
+To add an attribute to all spans and transactions, use the `BeforeSendTransaction` callback:
+
+```csharp
+options.SetBeforeSendTransaction(transaction =>
+{
+    transaction.SetData("environment-data", GetEnvironmentData());
+    return transaction;
+});
+```