feat: add the ability to choose default collection (#3029)

Co-authored-by: Tom Moor <tom@getoutline.com>
Co-authored-by: Tom Moor <tom.moor@gmail.com>

app/models/Team.ts

@@ -27,6 +27,10 @@ class Team extends BaseModel {
   @observable
   documentEmbeds: boolean;
 
+  @Field
+  @observable
+  defaultCollectionId: string | null;
+
   @Field
   @observable
   guestSignin: boolean;