feat(dotnet): document sending attachments with transactions

docs/platforms/dotnet/common/enriching-events/attachments/index.mdx

@@ -77,6 +77,12 @@ Attachments are retained for 30 or 90 days, based on [your plan's data retention
 
 Learn more about how attachments impact your [quota](/pricing/quotas/).
 
+### Sending Attachments with Transactions
+
+By default, scope attachments are only sent with error events, not with transactions. To also send an attachment with transactions, set `addToTransactions` to `true` when you create the `SentryAttachment`, then add it to the scope:
+
+<PlatformContent includePath="enriching-events/attachment-add-to-transactions" />
+
 ### Access to Attachments
 
 To limit access to attachments, navigate to your organization's **General Settings**, then select the _Attachments Access_ dropdown to set appropriate access — any member of your organization, the organization billing owner, member, admin, manager, or owner.

platform-includes/enriching-events/attachment-add-to-transactions/dotnet.mdx

@@ -0,0 +1,26 @@
+```csharp
+// Create an attachment that is also sent with transactions
+var attachment = new SentryAttachment(
+    AttachmentType.Default,
+    new FileAttachmentContent("your/path/file.log"),
+    fileName: "file.log",
+    contentType: null,
+    addToTransactions: true);
+
+// Add it to the scope - it's now sent with both events and transactions
+SentrySdk.ConfigureScope(scope => scope.AddAttachment(attachment));
+```
+
+```fsharp
+// Create an attachment that is also sent with transactions
+let attachment =
+    SentryAttachment(
+        AttachmentType.Default,
+        FileAttachmentContent("your/path/file.log"),
+        "file.log",
+        null,
+        addToTransactions = true)
+
+// Add it to the scope - it's now sent with both events and transactions
+SentrySdk.ConfigureScope(fun scope -> scope.AddAttachment(attachment))
+```