Additional layer(s) with prepackaged RTOS?

[nwf]

After talking with @gcloughley, I wonder if we should have an additional layer on top of the existing stack that also provides a snapshot of the RTOS and a sensible setting for the CHERIOT_RTOS_SDK environment variable we tend to use for xmake include()-s. It'd remove the need for users to separately clone the RTOS before building their application.

If that seems like a good idea, we might go a step further as well and add an additional layer on top of that with additional board support, either beside the RTOS or landed directly into the RTOS sdk/boards and sdk/includes/platform directories?)

[davidchisnall]

This is what the template repository that Adam has been working on is for.