…hese work on several

 different MCUs. Documentation for building and running is in lora_spi_send.rs.

- moved memoryMaps into examples/.

- uncommented portions of workflow rust.yml that had mistakenly been comment out.

- updated libusb-sys to version 0.2 and added  optional=true but unsure what
  "Fix for libusb-sys package discovery" was thus why "https://github.com/cmsd2/libusb-sys" was used.
  This change and related rust.yml update to "libusb-1.0-0" fix some CI errors but there remains
  an obscure "dpkg: error: need an action option" in rust.yml "Install libusb (apt armv7)".

- cleaned up some rust.yml for running examples.

- added feature  example = [] used as gate to prevent cargo "test" and "cargo build --examples"  from
  attempting to build unless appropriate features ar also specified.

…pendabot. (Could not get merge of dependabot pull request to work because of habitual CI error.)

…tm32f411.

update  to rust-radio-sx127x-0.11.0  using radio-0.9.0