RFC: structuring forums for best use for swift-evolution

Hi! I hope I sent this email correctly and it entered the RFC thread
started by Ted.

My pitch: what about timeline of thread as a category? Like this:
- Short term: for current release of Swift, aka 4.1 after 4.0 is released.
- Mid term: for next release of Swift, aka 4.0 now, because 3.x is the
current release.
- Long term: for releases far away. Pertaining Swift 5.0 now, or Swift 6.0,
7.0 and such.

I think it’s at least useful as a divider between different topics, because
depending on the timeline, the planning process and base priority of the
threads should be different.

— Félix