wgpu-0.17 uprev

No functional changes, other than slightly softer limits for the voxel tracing path.
Main thing for the release is the upgrade from wgpu-0.13 to wgpu-0.17

Voxel tracing and debug UI

This release features a practical way of rendering the terrain from any angle, including 1st person, and shadows - voxel tracing.
It also has debug UI with a lot of interesting configuration, such as an ability to swap the mechos.

WGSL shaders

This release has the main shaders ported to WGSL. This means, glsl-to-spirv toolchain is retired, and we get the most optimal path on all platforms, including the Web.

This is the first version of the game that is redistributable. Previously, the weirdness of glsl-to-spirv was blocking the program to be copied around.