Documentation

I noticed thishere. There are currently 4 ways to refer to the FT build:

• "free threaded" (11 uses)
• "free threading" (10 uses)
• "free-threaded" (9 uses)
• "free-threading" (1 hit)

Ideally, we should be consistent. I guess there are two things to solve here:

1. Should there be a hyphen?
2. Should it be the "free(-)threaded build" or the "free(-)threading build"?