Add migrations to fix error not creating tables

Author: lulunac27a

app.py

@@ -4,6 +4,7 @@
 import os
 from typing import Union
 from flask import Flask, flash, render_template, request, redirect, url_for
+from flask_migrate import Migrate, migrate
 from flask_sqlalchemy import SQLAlchemy
 from sqlalchemy import text
 from sqlalchemy.orm.relationships import RelationshipProperty
@@ -15,6 +16,7 @@
 app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
 app.secret_key = os.environ["SECRET_KEY"]
 db = SQLAlchemy(app)
+migrate = Migrate(app, db)
 
 
 class User(db.Model):