[feature]: add quickstart doc for express-postgresql-prisma sample app

[Abbhiishek]

👀 Is there an existing feature request for this?

• [X] I have searched the existing issues

🔖 Enhancement description

Quickstart guide for https://github.com/keploy/samples-typescript/tree/main/express-postgresql-prisma

🎤 Why should this be worked on?

A sample app documentation on how to test a express app with prisma as ORM

💻 Repository

docs