Include unicode-range for all CSS files

[jwr1]

Currently, the unicode-range property is only provided for the [weight].css files. I suggest we provide the property for all CSS files so the browser can dynamically filter out unused font subsets.

[ayuhito]

The only blocker for this is the lack of information on what unicode-range's certain languages cover. The current information we have is insufficient to determine the optimal ranges for each subset as CJK fonts are split into numbered subsets. So we will need to find a way to analyze the font files for the correct information. Would appreciate some suggestions for this.

[ayuhito]

This is doable if we follow how Wakamai Fondue implements its font analysis tooling.

This a gold mine of a website and there's lots to learn from it! I'm sure we can implement a bunch of the features from there too.