Thoughts on line grids and line spacing proposals

After the discussion in Paris that we had about CSS Rhythm and other
line spacing issues [1], I decided to write down a bit more detail
about both:

 (a) fleshing out the proposal I made there about using the ideas
     from line-box-contain for a better line spacing model, and

 (b) my thoughts on the existing proposals around line grid and
     rhythm, and which pieces of each could be taken to form a first
     version to address the use cases that motivated these drafts.

I've thus written this document:
https://github.com/dbaron/css-line-spacing/blob/master/explainer.md
with some background, and thoughts on how we might combine pieces of
these proposals.

I think this may be worth talking about when we meet at TPAC in a
little over a month, but I'm also happy to get feedback before then.
Probably github issues in the repository [2] work for feedback,
although they're not necessarily particularly permanent since the
document may end up moving.

-David

[1] https://lists.w3.org/Archives/Public/www-style/2017Sep/0003.html
[2] https://github.com/dbaron/css-line-spacing/issues

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
             Before I built a wall I'd ask to know
             What I was walling in or walling out,
             And to whom I was like to give offense.
               - Robert Frost, Mending Wall (1914)