[css-fonts] Add COLRv1 keyword to <color-font-technology> production #6329
Description
Context: On the background of our plans to introduce COLR v1 color fonts we have requests from partner for feature detection for font formats, in particular COLRv1.
To the line
<color-font-technology> = [COLR | SVG | sbix | CBDT ]
I suggest to add a specific item COLRv1 or COLRV1.
Reasoning: Table version 1 brings a whole set of a new capabilities that differs from table version 0 graphical capabilities (think flexible vector graphics (v1) vs. stacked uni-colored glyph layers (v0)). UAs should be able to distinguish and load only the right supported font based on the supports sequence of the format() function in the @font-face src: line.