[css-fonts-4] incorporate css-font-display draft into css-fonts-4

[dbaron]

We apparently had a resolution to take Tab's css-font-display to FPWD, although I can't find the resolution in any minutes (although I do vaguely remember it).

Then we had an agenda item that included, instead, possibly including it in fonts-4.

The minutes of the discussion of that item don't seem to include discussion of that topic or any resolution on it.

It seems like we should have a resolution one way or the other so that the font display feature can make progress, since my understanding is that it already has 2 disabled implementations (Gecko and I think Chromium) that are waiting for spec progress to enable the code.

/cc @tabatkins @upsuper

[kojiishi]

@KenjiBaheux

[litherum]

I plan to incorporate it into fonts-4 very soon. I don't think this needs a resolution.

[litherum]

Relatedly, there is already an agenda item for taking fonts-4 to FPWD at the F2F. I plan to incorporate it before the F2F, so the FPWD would include font-display.