cargo-embed → probe-rs documentation change

[BobAdamsEE]

Attempting to install cargo-embed with instructions from the current boards/atsamv71_xult/README.md lead to the following:

  `cargo-embed` is now a part of `probe-rs`. To install it, run the following PowerShell command:

  irm https://github.com/probe-rs/probe-rs/releases/latest/download/probe-rs-tools-installer.ps1 | iex

  Once installed, you can use the "cargo embed" command just like before, although there might be minor changes in the API. For more information, please refer to the documentation at https://probe.rs/docs/tools/cargo-embed/.

Updated boards/atsamv71_xult/README.md with the relevant instructions for probe-rs for Windows / Linux.

[BobAdamsEE]

This will need further work - probe-rs has issues with the Embed.toml from changes from the initial cargo-embed. Will submit again once I get flashing working.

[michalfita]

I'm not author of this demo and I don't use it, hence missed the change that seem to happen in 2023. Thanks for efforts to improve the documentation.

[BobAdamsEE]

Resolved review comments and updated Embed.TOML to handle some changes from probe-rs:

• Update Embed.toml flashing options probe-rs/probe-rs#2419 - halt_afterwards removed from default.flashing section
• Rtt refactor vol 2 probe-rs/probe-rs#2249 - show_timestamps and channel parameter changes in refactor