Merge branch 'jokester-patch-1'

Author: kamilmysliwiec

content/openapi/introduction.md

@@ -42,6 +42,8 @@ async function bootstrap() {
 bootstrap();
 ```
 
+> info **Hint** `document` (returned by the `SwaggerModule#createDocument()` method) is a serializable object conforming to [OpenAPI Document](https://swagger.io/specification/#openapi-document). Instead of hosting it via HTTP, you could also save it as a JSON/YAML file, and consume it in different ways.
+
 The `DocumentBuilder` helps to structure a base document that conforms to the OpenAPI Specification. It provides several methods that allow setting such properties as title, description, version, etc. In order to create a full document (with all HTTP routes defined) we use the `createDocument()` method of the `SwaggerModule` class. This method takes two arguments, an application instance and a Swagger options object.
 
 Once we create a document, we can call the `setup()` method. It accepts:

content/techniques/mongo.md

@@ -87,6 +87,8 @@ In case there are multiple owners, your property configuration should look as fo
 ```typescript
 @Prop({ type: [Types.ObjectId], ref: Owner.name })
 owner: Owner[];
+```
+
 Finally, the **raw** schema definition can also be passed to the decorator. This is useful when, for example, a property represents a nested object which is not defined as a class. For this, use the `raw()` function from the `@nestjs/mongoose` package, as follows:
 
 ```typescript