Google Code-in

During GCI it has become apparent that we need to better highlight how to create good image assets for new content :-)

Typical problems:

• Not sizing an image square and using a power of two (16x16, 32x32, 64x64..) plus not necessarily considering an objects dimensions (pad sides? Align diagonally?)
• Using an image editor that does not support transparency (possibly just to resize the image, causing the background to go solid white)
• Finding 3rd party image assets that have a non-transparent background, not knowing how to make it transparent
• Finding 3rd party image assets that are not clearly licensed (have to work with CC BY 4.0 or more open, like CC 0 / Public Domain)
• Not knowing how to attribute a 3rd party image well (must put a link to a page about the image in a readme, not a direct link to the image)
• Not being aware of handy search resources like using Google Image Search with an option to only return results fitting a usage criteria, or knowing about some typically useful sites that host large amounts of usable images

We have some resources in the other tasks requiring the inclusion of new images, and the readmes in modules like Cooking or Equipment have good attribution/credit lists.

I'd like to have a page added to https://github.com/Terasology/TutorialAssetSystem/wiki (can temporarily keep it in a personal repo wiki) to help cover this topic. Consider linking to pages like https://github.com/MovingBlocks/Terasology/wiki/Paint.NET to cover tool specific details :-)