[css-inline-3] Drop 'hebrew' alignment from initial-letter-align

[fantasai]

As we were drafting up initial-letter-align, we added a hebrew value to represent the correct alignment for the Hebrew script, whose top alignment point coincides with neither the x-height, nor the cap height. Numerous writing systems have this problem: their top edge has no corresponding font metric. So we also have a generic issue about supporting writing systems other than Latin, CJK, and certain Indic derivatives that use the hanging baseline; and Hebrew was a sort of specific placeholder for this problem so we could work out some of the details.

Given OpenType still doesn't have metrics for Hebrew (or Thai or a number of other writing systems), and we're tightening up the spec overall, I think it makes sense to drop this value from the spec for now but keep the examples and the generic issue open. We still need a solution for the problem, but ideally one that scales to all the writing systems as yet unsupported. In the meantime, while it's been useful to have it kicking around as we work out the system overall, I think it's time to trim the value space down to what is currently possible to implement based on existing font metrics so that the reality of the missing capability is clearer.

[fantasai]

Turns out we don't have a generic issue in GH, just a big red notice in the spec. :) Filed one at #5244

[css-meeting-bot]

The CSS Working Group just discussed Drop hebrew alignment from initial-letter-align, and agreed to the following:

• RESOLVED: remove hebrew value from initial-letter-align

The full IRC log of that discussion

<fantasai> Topic: Drop hebrew alignment from initial-letter-align
<fantasai> github: https://github.com//issues/5208
<emilio> fantasai: we have some values handling hebrew in initial-letter-align as a placeholder
<emilio> ... because we don't have metrics for it and a couple other writing systems
<emilio> ... we put it in the spec along with an issue on those lines
<fantasai> https://github.com//issues/5244
<emilio> ... as we're cleaning up the spec I think we should remove the hebrew values and leave the issue about the writing systems not having metrics available
<emilio> ... so that we don't have this value which is not implementable at the moment
<emilio> dauwhe: we tried to reach out to the hebrew community and we couldn't even name the alignment point
<emilio> florian: I'd say let's remove it given we have an issue to having this
<emilio> fantasai: I think it was useful as we explored the space to know where we needed to hook it in, but now it's not so much
<emilio> RESOLVED: remove hebrew value from initial-letter-align

[fantasai]

Closed in favor of following up via #5244