out of scope proposals

Hey all - I haven't been keeping up for a few months, but I just found a
small change in my swift-evolution repo that I made in response to a thread
here, but I obviously got distracted because I never committed it.

I added a file to track out-of-scope proposal discussions (idea is it would
link to threads on this list, and possibly other places), and linked it
from the README.

Would this still be useful? Shall I make a PR with it or just bin it?