Swag-for-dev: Add gitpod configuration file

[aslafy-z]

Gitpod allows people to start hacking just by loading a page. It contains a vscode like IDE which already has the repository loaded, the right dependencies available, configured test command, and allows to expose ports to the internet.

See the docs in here: https://www.gitpod.io/docs/configuration/

[nisarhassan12]

I will soon make a Pr for this.