Publish useful safe patterns, e.g. compile-time deadlock prevention

[PLeVasseur]

A guide about how to implement useful safe patterns for safety-critical software

[jmqd]

@PLeVasseur , I can take a stab at this!

[PLeVasseur]

Sounds great! Feel free to use a new folder under initiatives/ for this for now and as it bakes we can see if it needs to go anywhere specific.