fix(typings): model init returns model class, not instance (#13214)

types/lib/model.d.ts

@@ -1622,10 +1622,10 @@ export abstract class Model<TModelAttributes extends {} = any, TCreationAttribut
    * @param options These options are merged with the default define options provided to the Sequelize constructor
    * @param options These options are merged with the default define options provided to the Sequelize constructor
    * @return Return the initialized model
    * @return Return the initialized model
    */
    */
-  public static init<M extends Model>(
-    this: ModelStatic<M>,
+  public static init<MS extends ModelStatic<Model>, M extends InstanceType<MS>>(
+    this: MS,
     attributes: ModelAttributes<M, M['_attributes']>, options: InitOptions<M>
     attributes: ModelAttributes<M, M['_attributes']>, options: InitOptions<M>
-  ): Model;
+  ): MS;
 
 
   /**
   /**
    * Remove attribute from model definition
    * Remove attribute from model definition

types/test/model.ts

@@ -52,7 +52,7 @@ MyModel.update({}, { where: { foo: 'bar' }, paranoid: false});
 
 
 const sequelize = new Sequelize('mysql://user:user@localhost:3306/mydb');
 const sequelize = new Sequelize('mysql://user:user@localhost:3306/mydb');
 
 
-MyModel.init({
+const model: typeof MyModel = MyModel.init({
   virtual: {
   virtual: {
     type: new DataTypes.VIRTUAL(DataTypes.BOOLEAN, ['num']),
     type: new DataTypes.VIRTUAL(DataTypes.BOOLEAN, ['num']),
     get() {
     get() {