Support using cargo-embed as a custom cargo runner

[JoshMcguigan]

Is your feature request related to a problem? Please describe.

I'd like to be able to configure cargo-embed as a custom cargo runner, so cargo run can automatically use cargo-embed.

Describe the solution you'd like

In .cargo/config.toml:

runner = "cargo embed --maybe-some-new-arg-to-support-this-feature"

Describe alternatives you've considered

1. Run cargo embed rather than cargo run

[matteocarnelos]

You can use probe-run:

runner = "probe-run --chip <YOUR_CHIP>"

[JoshMcguigan]

Hi, thanks for the suggestion! I considered probe-run, but I wanted to stick with cargo-embed since at the moment probe-run doesn't act as a gdb server.

Although I've since run into probe-rs/probe-rs#1375 which is blocking gdb usage for me via cargo-embed anyway - so perhaps I'll give probe-run a go now.