message: Fix wrong documentation
  fixes wrong documentation (adds a "typeof" where it was needed)
  this is a squash merge of typegoose/typegoose#58
diff: @@ -13,7 +13,7 @@ class Kitten {
  @prop()
  public name?: string;
  - public static findByName(this: ReturnModelType<Kitten>, name: string) { // this is an Instance Method
  + public static findByName(this: ReturnModelType<typeof Kitten>, name: string) { // this is an Instance Method
  return this.find({ name }).exec(); // thanks to "ReturnModelType" "this" has type infomation
  }
  }
  