rpi-loader-ota 0.3.1

Changed

• Moved into joeferner/rpi-hal,
  with the loader; the old rpi-loader repository is archived. The
  manifest's repository points there and its new homepage at
  https://joeferner.github.io/rpi-hal/crates/loader/. Releases from here
  are tagged loader-ota-v<version>. No API or bundle-format change.