[Backend] Setup migrations for database

It's always good to have the migrations to keep track of changes to the database.
You can check the article how to set it on Sequelize : https://sequelize.org/master/manual/migrations.html

The configuration for sequelize is [here](https://github.com/adarshaacharya/CsOverflow/blob/main/server/config/sequelize.config.ts) .

If you want to work on this issue please leave comment below I'll assign it to you. Also, if you face any problems in setting the database locally please comment below I'll guide you !

Read [Contributing guidelines](https://github.com/adarshaacharya/CsOverflow/blob/main/CONTRIBUTING.md) for further info about how to make contribution.