Minor: add a record API subscription example for dotnet and clean up other dotnet examples.

docs/src/content/docs/documentation/APIs/record_apis.mdx

@@ -291,6 +291,7 @@ updates, and deletions.
 
 import subscribeDartCode from "@examples/record_api_dart/lib/src/subscribe.dart?raw";
 import subscribeTsCode from "@examples/record_api_ts/src/subscribe.ts?raw";
+import subscribeDotnetCode from "@examples/record_api_dotnet/Subscribe.cs?raw";
 
 <Tabs>
   <TabItem label="JS/TS">
@@ -300,6 +301,10 @@ import subscribeTsCode from "@examples/record_api_ts/src/subscribe.ts?raw";
   <TabItem label="Dart">
     <Code lang="dart" code={subscribeDartCode} />
   </TabItem>
+
+  <TabItem label="C#/.NET">
+    <Code lang="cs" code={subscribeDotnetCode} />
+  </TabItem>
 </Tabs>
 
 ### Schema