[css-fonts-4] Open issues about font-display

[frivoal]

font-display has a bunch of issues which are only tracked in Tab's personal repo.
https://github.com/tabatkins/specs/issues?utf8=%E2%9C%93&q=is%3Aissue%20is%3Aopen%20%5Bcss-font-display%5D

They should be migrated over here and discussed, especially since both Chrome and Firefox have implementations that they want to ship.

/cc @tabatkins @litherum @dbaron

[frivoal]

Opened an issue here for each of the issues in Tab's repo. They should be discussed individually. Closing this meta one.