message: docs(error-warnings-details): improve E016 Details
  typegoose/typegoose#478
diff: @@ -170,6 +170,15 @@ Error: `Type does not have an valid "OptionsConstructor"! (${getName(loggerType)
  Details:
  The `Type` provided does not have an property `OptionsConstructor` (`undefined / null`), this is required to map options of an array & map
  +Typegoose uses the property [`OptionsConstructor`](https://github.com/Automattic/mongoose/tree/master/lib/options) on types (ex `mongoose.Schema.Types.ObjectId.OptionsConstructor`) to correctly map the options (from `@prop(options)`) to the appropiate place
  +
  +If custom types are used and they dont have `OptionsConstructor`, and easy way to workaround this error is the following:
  +
  +```ts
  +mongoose.Schema.Types.Custom.OptionsConstructor = {}; // only do this if really necessary
  +mongoose.Schema.Types.Custom.OptionsConstructor = mongoose.SchemaTypeOptions; // prefer this if possible
  +```
  +
  ### Setting "Mixed" is not allowed [E017]
  Error: `Setting "Mixed" is not allowed! (${name}, ${key}) [E017]`
  