Merge pull request #2517 from arkist/mongoose-document

docs(mongo): change the way to define the mongoose document interface

Author: kamilmysliwiec

content/techniques/mongo.md

@@ -34,9 +34,9 @@ Let's define the `CatSchema`:
 ```typescript
 @@filename(schemas/cat.schema)
 import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
-import { Document } from 'mongoose';
+import { HydratedDocument } from 'mongoose';
 
-export type CatDocument = Cat & Document;
+export type CatDocument = HydratedDocument<Cat>;
 
 @Schema()
 export class Cat {