-- started out from the e-ink-hello example on https://github.com/ImplFerris/esp32-projects
cargo install espup --locked
cargo install espflash --locked
espup install --name book-1.0.0 --toolchain-version 1.90.0
# should do the right thing due to toolchain config
cargo build --release
espflash flash --monitor --chip esp32s3 --log-format defmt target/xtensa-esp32s3-none-elf/release/e-ink-spotprices