Tutorial:Modding tutorial/Gangsir

This is a modding tutorial for Factorio version 0.15. In this tutorial, the author will explain how Factorio works behind the scenes, how to modify Factorio, where to find documentation, and explain concepts.

Overview

Before we start the tutorial, a few things to note:

Code tinted green like this should be included into the mod this tutorial is going to create; If the reader follows along with it. The best way to do this is to copy and paste, to ensure faithful reproduction.
Whenever code is added to the mod, a Lua comment with the file name will be at the beginning of the green box. Place the code in the box into that file. Eg:
--control.lua

Code tinted purple like this should not be included into the mod, it's just for educational/example purposes, and to boost understanding.

This tutorial was created for version 0.15, so any viewers in the future should take note that some minor changes may have been made, and should look at the changelogs up to the current version.