Merge pull request #1256 from ably/update/json-serialize-readme

Fix readme

README.md

@@ -235,6 +235,21 @@ if (result.IsFailure)
 }
 ```
 
+- When calling `channel.Publish` with a dotnet object instance as the message data, the library will use the Newtonsoft Json.NET library to serialize the message with default serialization settings.
+- If you need to use custom seralization settings, you can apply the serialization yourself and send the resulting string as the message data:
+
+```csharp
+var serializedData = JsonConvert.SerializeObject(message,
+    new JsonSerializerSettings
+    {
+        ContractResolver = new CamelCasePropertyNamesContractResolver()
+    });
+
+var ablyMessage = new Message("name", serializedData) {Encoding = "json"};
+
+channel.Publish(ablyMessage);
+```
+
 ### Getting channel history
 
 Calling history returns a paginated list of message. The object is of type `PaginatedResult<Message>` and can be iterated through as a normal list.  
@@ -331,6 +346,22 @@ catch(AblyException ablyError)
 }
 ```
 
+- When calling `channel.PublishAsync` with a dotnet object instance as the message data, the library will use the Newtonsoft Json.NET library to serialize the message with default serialization settings.
+- If you need to use custom seralization settings, you can apply the serialization yourself and send the resulting string as the message data:
+
+```csharp
+var serializedData = JsonConvert.SerializeObject(message,
+    new JsonSerializerSettings
+    {
+        ContractResolver = new CamelCasePropertyNamesContractResolver()
+    });
+
+var ablyMessage = new Message("name", serializedData) {Encoding = "json"};
+
+channel.Publish(ablyMessage);
+```
+
+
 ### Querying channel history
 
 ```csharp