Mid-Level Rendering w/ `ShaderModel` #773

Job	Run time
nix-fmt-check	22s
nix-flake-check (ubuntu-latest)	29s
cargo (cargo fmt --verbose --all -- --check)	1m 2s
nix-flake-check (macos-latest)	57s
cargo (cargo check --locked --workspace)	4m 3s
cargo (cargo check --locked --examples --workspace)	4m 42s
cargo (cargo test --locked --lib --bins --workspace --features "egui")	10m 3s
cargo (cargo doc --locked --workspace --features "egui")	7m 35s
cargo (cargo test --locked -p nannou_core --no-default-features --features "libm serde")	1m 6s
cargo (mdbook build guide/)	54s
cargo (cargo test --locked -p book_tests)	7m 3s
verifications	1s
cargo-publish	0s
guide-push-to-deploy	0s
	38m 17s

Provide feedback