Add DebugAssist option for protecting memory on C3

[georgik]

C3 has very little memory. When people are porting applications or adding new crates they might run into memory problems.
Consider introducing DebugAssist to the template to simplify steps when porting application to C3.

Sample code: https://github.com/georgik/esp32-memory-limit/blob/main/examples/12-alloc-stack-overflow-protection.rs#L37

[bjoernQ]

Maybe #45 is an even easier way to get a similar experience (and much easier to implement in the template)