Create a written tutorial about using the Gateway contract

[Atanda1]

User Story
As a developer, I want to build the withdrawal feature for my stablecoin savings app. It uses paycrest to off-ramp from USDT to Nigerian naira.

Tech Details

• This article will cover how to integrate our gateway contract into an external app to enable off-ramp for users. Go into our docs and open guides/GatewayOrders.md to understand how to make use of the contract to create off-ramp orders.
• For the article, build a demo app with UI that shows the how to interact with the contract in the savings app.
• Add a step-by-step tutorial that explains how to build everything from scratch.
• Submissions should be submitted for review using a dropbox link.

Notes/Assumptions

• Add the repo of the demo app
• Here's a good sample of what we expect our tutorials to look like - https://blog.logrocket.com/integrate-web3-into-vue/