A mostly faithful and compatible port of the bin/focus-send tool in Kaleidoscope to Rust. It's interface compatible: takes the same input, and produces the same output. The major difference is that this version of the tool writes data in 32-byte chunks (like Chrysalis), and can auto-detect the device to use.
Otherwise, the usage is simple: focus-send COMMAND ARGUMENTS...
The COMMAND is the Focus command to send, with optional arguments. In case
there are multiple supported devices, the tool defaults to using the first one.
If that is not desirable, the --device (or -d) argument can be used to
specify the device to connect to. To remain compatible with Kaleidoscope's
bin/focus-send, we can also use the DEVICE environment variable for the same
purpose.