chore: Add 16x16 sample tiff for testing/benchmarking

fix: correctly derive centre of input .tiff

fix: .tiff output type and size

feat: Create DB indexes post compute

refactor: e2e tests for sqlite storage

feat: sqlite storage engine

feat: Load and save tiles with `gdal`

tests: Flesh out CPU kernel surfaces test

test: scale and observer_height tests

fix: issues with `time` not interpreting env var

fix: run benchmark with RUSTFLAGS to guarantee benchmark correctness

add Blelloch's paper credit in README

docs: update README since new CPU kernel

feat: set CPU backend as default TVS backend

chore: add option to disable image rendering