Copy hello_serial into bootloaders/encrypted

[will-v-pi]

Removes the dependence on a file from a separate folder, which other examples don't have

This would allow the example to be used in the VS Code extension, as that needs examples to be contained in a single directory

[lurch]

This would allow the example to be used in the VS Code extension, as that needs examples to be contained in a single directory

Does this also mean that some of the "universal examples" aren't buildable with VS Code? Or is that a non-issue as the VS Code extension doesn't support all the other "infrastructure" needed by those examples anyway?

[will-v-pi]

Yeah, those aren't included in the VS Code extension yet, as they need both Arm and Risc-V toolchains. I think it'll be simpler to just add an option to make any binary universal in the extension, rather than including the examples

[kilograham]

I don't know that "universal" binary is that common a feature in general.