Update guide.md

Docs for `bosk-jackson`

docs/guide.md

@@ -555,7 +555,7 @@ The collection is called `boskCollection` and the document has four fields:
 The format of the `state` field is determined by `BsonPlugin`.
 The code for `BsonPlugin` will have the details, but some high-level points about the BSON format:
 
-- It does not match the JSON format generated by `bosk-gson`. The two are not mutually compatible. This is a deliberate decision based on differing requirements.
+- It does not match the JSON format generated by `bosk-jackson` or `bosk-gson`. This is a deliberate decision based on differing requirements.
 - It strongly favours objects over arrays, because object members offer idempotency and (ironically) stronger ordering guarantees.
 
 ##### Schema evolution: how to add a new field
@@ -621,11 +621,27 @@ These rules require that the driver maintains an awareness of the current bosk s
 and so most drivers are rarely able to take advantage of these options,
 because they can't generally determine what effect an update will have.
 
-### Serialization: `bosk-gson`
+### Serialization: `bosk-jackson` and `bosk-gson`
 
-The `bosk-gson` module uses the Gson library to support JSON serialization and deserialization.
+The `bosk-jackson` and `bosk-gson` modules use the Jackson and Gson libraries to support JSON serialization and deserialization.
 
-#### Configuring the Gson object
+#### Configuring Jackson
+
+To configure an `ObjectMapper` that is compatible with a particular `Bosk` object, use the `JacksonPlugin.moduleFor` method.
+Here is an example:
+
+``` java
+JacksonPlugin jacksonPlugin = new JacksonPlugin();
+boskMapper = new ObjectMapper()
+	.registerModule(jacksonPlugin.moduleFor(bosk))
+
+	// You can add whatever configuration suits your application:
+	.enable(INDENT_OUTPUT);
+```
+
+`JacksonPlugin` is compatible with many of the `ObjectMapper` configuration options, so you should be able to configure it as you want.
+
+#### Configuring Gson
 
 To configure a `Gson` object that is compatible with a particular `Bosk` object, use the `GsonPlugin.adaptersFor` method.
 Here is an example:
@@ -636,14 +652,14 @@ boskGson = new GsonBuilder()
 	.registerTypeAdapterFactory(gsonPlugin.adaptersFor(bosk))
 
 	// You can add whatever configuration suits your application.
-	// We recommend these.
+	// We recommend these:
 	.excludeFieldsWithoutExposeAnnotation()
 	.setPrettyPrinting()
 
 	.create();
 ```
 
-Note that `GsonPlugin` is compatible with many of the Gson configuration options, so you should be able to configure it as you want.
+`GsonPlugin` is compatible with many of the Gson configuration options, so you should be able to configure it as you want.
 
 #### Format