message: docs(faq): add question about how to use "id" over "_id"
  This is a squash merge of typegoose/typegoose#394
diff: @@ -37,3 +37,16 @@ A: because Typegoose doesn't modify any Mongoose code, it is still the same as M
  ### Why is 7.4.x constrained to mongoose 5.10.18?
  A: this because in mongoose 5.10.19 and higher, mongoose has its own typescript definitions, and typegoose is not upgraded for that yet
  +
  +## Edge Cases
  +
  +### I want to the return document with property `id` instead of `_id`
  +
  +Mongoose automatically adds an virtual named `id`, use the following for type definitions:
  +
  +```ts
  +class Cat {
  + id: mongoose.Types.ObjectId;
  + _id: mongoose.Types.ObjectId;
  +}
  +```
  