Dev Env setup Tutorial

[namithj]

Tutorial for devs on how to setup the Dev environment like they are entirely new to the process.

All the pre requirements to running composer install should be covered.

This can help everyone get upto speed easily and reduce the entry bar.

[namithj]

Installation and usage

Installing composer

Linux & Mac:
`curl -sS [https://getcomposer.org/installer](https://getcomposer.org/installer) | php`
Windows installer:
Visit `https://getcomposer.org/download/` and download the `Composer-Setup.exe`

Using composer

`composer install` : Initially run to setup all dependencies.
`composer lint` : Checks the plugin files as per WPCS rules adopted by the plugin team
`composer format` : Format the plugin files as per WPCS rules adopted by the plugin team
`composer test` : Run Unit tests on the plugin code.