Use a second vertex buffer for instances

[expenses]

Assuming you have a second VertexBufferDescriptor set with InputStepMode::Instance, you can simply set an instance buffer like so:

render_pass.set_vertex_buffer(1, &self.instance_buffer.slice(..));

This is a lot easier than adding it to the bind group like you're doing in the instancing tutorial.

[sotrh]

You are correct. I originally showcased multiple methods of instancing, including using a texture. I used storage buffers as the default method, as I was interested in them at the time.

I'm thinking of switching to using vertex buffers for instancing, but I'm currently busy getting wgpu to work with wasm-pack. You're welcome to make a pull request.

[sotrh]

Fixed in #126