Tab stops set to 4 in github.

[cheako]

After some googling I've discovered that appending ?ts=4 to URLs makes the code render correctly.
https://github.com/KhronosGroup/Vulkan-Samples/blob/master/samples/apps/atw/atw_vulkan.c?ts=4

Setting this at the project/file level in github would be preferred. Contact github for how to implement this.