initial attempt to implement power button press option

Introduced attempt to implement power button functionality

The power button event from acpid seems to have an inconsistent name - includes additional numbers, possibly scankeys?

To do this simply, I used string.contains. However, match statement in rust doesn't seem to work with plain expressions, which required the use of an if/else construct. May be missing something - surely feels like there's a cleaner way, but haven't found answers in documentation or online (https://doc.rust-lang.org/reference/expressions/match-expr.html and https://doc.rust-lang.org/reference/patterns.html).

Comments/suggestions gladly accepted.